Salam,
Both Christian and Muslim believe and strive to do good deeds in this world in order to have an eternal life in the hereafter by entering heaven. Apart from doing good deeds there are extra requirements that both faithful must fulfill.
As for the Christian, to enter heaven they have to believe that Jesus is God that was why with the grace and mercy of God, He sent His only begotten son Jesus to be sacrificed on the cross and to die for the sins of human kind. The belief that Jesus is God is taken from the Bible which says that:
Jesus saith unto him, I am the way, the truth, and the life: no man cometh unto the Father, but by me. (John 14:6)
For God so loved the world, that he gave his only begotten Son, that whosoever believeth in him should not perish, but have everlasting life. (John 3:16)
Therefore to gain salvation a Christian has to confess his sins and to believe that Jesus died for his sins. Everyone will not be free of sin and has to confess his sins as stated in the following verses of the Bible:
That if thou shalt confess with thy mouth the Lord Jesus, and shalt believe in thine heart that God hath raised him from the dead, thou shalt be saved. For with the heart man believeth unto righteousness; and with the mouth confession is made unto salvation. (Roman 10:9-10)
For all have sinned, and come short of the glory of God; being justified freely by his grace through the redemption that is in Christ Jesus. (Roman 3:23-24)
In Islam, to have an eternal life and to enter heaven a Muslim have to uphold the commandments, he is to believe and worship only one God Allah. And Allah says about Himself in His Book the Quran He is the Creator of everything as He created the human and thus He commanded human to worship Him as stated in the following verses:
I have only created Jinns and men that they may worship Me. (Surah 51:56)
"Verily, I am Allah: There is no god but I: So worship thou Me (only), and establish regular prayer for celebrating My praise. (Surah 20:14)
However to gain salvation the Muslims are not to idolize any other being besides or along with Allah. To God the most heinous crime is to put partners beside Him and this is stated clearly in the teaching of the Quran as follows:
Allah forgives not that partners should be set up with Him; but He forgive anything else to whom He please; to set up partners with Allah is to devise a sin most heinous indeed. (Surah 4:48)
Allah forgives not (the sin of) joining other gods with Him; but He forgive whom He please other sins than this: one who joins other gods with Allah, Hath strayed far, far away (from the right). (Surah 4:116)
However with the grace and mercy of Allah the door of repentance is always open and he who repent, He will forgive as He will, depending on our sincerity. For only God knows our innermost thoughts.
"But, without doubt, I am (also) He that forgives again and again, to those who repent, believe, and do right, who, in fine, are ready to receive true guidance."
(Surah 20:82)
If any one does evil or wrongs his own soul but afterwards seeks Allah's forgiveness, he will find Allah Oft-forgiving, Most Merciful. (Surah 4:110)
The Christians worship the Father, the Holy Ghost and Jesus as God
Since Christians believe that Jesus is God, therefore they worship him as they worship God as they believe that God, Jesus and the Holy Ghost is one of the three in a trinity. They interpreted the following verses of the Bible in what is being said by Jesus is he is also God as the vision of God is in him:
Jesus saith unto him, have I been so long time with you, and yet hast thou not known me, Philip? He that hath seen me hath seen the Father; and how sayest thou then, Show us the Father? Believest thou not that I am in the Father, and the Father in me? The words that I speak unto you I speak not of myself: but the Father that dwelleth in me, he doeth the works. (John 14:9-10)
Jesus forgives sins and therefore he is God as only God can forgive sins and he is sinless. And the Christians believe that the Word which with God in the beginning was Jesus and the interpretation is, although Jesus was with God they are not separated but one and the same identity. The following verse of the Bible is taken to mean not only God was the beginning Jesus was there too in the beginning. The following verse of the Bible gives this interpretation:
In the beginning was the Word, and the Word was with God, and the Word was God. (John 1:1)
Since the Word is interpreted to be “Jesus” as the beginning in John 1:1 the meaning of the verse is therefore “In the beginning was Jesus and Jesus was with God and Jesus was God. With this interpretation however it deprived the beginning of the Holy Ghost as there will be an error of omission in the Bible.
It is also interpreted from the verses of the Bible that Jesus claim his kingdom is not of this world and that he is the savior of mankind and therefore he is God:
Jesus answered, my kingdom is not of this world: if my kingdom were of this world, then would my servants fight, that I should not be delivered to the Jews: but now is my kingdom not from hence. (John 18:36)
And the angel said unto them, Fear not: for, behold, I bring you good tidings of great joy, which shall be to all people. For unto you is borne this day in the city of David a Savior, which is Christ the Lord. (Luke 2:10-11)
The Christians worship Jesus is also because he is regarded as sinless and he is claimed to be the only begotten son of God and he is therefore God. The Bible says:
All human sins: For all have sinned, and come short of the glory of God; being justified freely by his grace through the redemption that is in Christ Jesus. (Roman 3:23-24)
Lovable God: For God so loved the world, that he gave his only begotten Son, that whosoever believeth in him should not perish, but have everlasting life. (John 3:16)
Thus the Christians believe that only through Jesus they will enter paradise without him no one will taste heaven.
The Muslims only worship Allah
On the other hand, Muslim worship only One God and there is no other representative besides Him, neither has He a son nor appear as a man but He is to be worshipped as an unseen God:
He is Allah, the one and only; Allah the eternal. Absolute; He beget not nor is he begotten; and there is none unto like Him (Surah 112)
No vision can grasp Him, but His grasp is over all vision: He is above all comprehension, yet is acquainted with all things. (Surah 6:103)
And Muslims believe that only God Allah can forgive sin none others and He is the First and He is the Beginning while His words which He taught His creatures come after that:
And those who, having done something to be ashamed of, or wronged their own souls, earnestly bring Allah to mind, and ask for forgiveness for their sins, and who can forgive sins except Allah? And are never obstinate in persisting knowingly in (the wrong) they have done. (Surah 3:135)
To Him belongs the dominion of the heavens and the earth: It is He Who gives Life and Death; and He has Power over all things. He is the First and the Last, the Evident and the Immanent: and He has full knowledge of all things.
(Surah 57:3-4)
And put thy trust in Him Who lives and dies not; and celebrate his praise; and enough is He to be acquainted with the faults of His servants. (Surah 25:58)
No Sustenance do I require of them, nor do I require that they should feed Me. For Allah is He Who gives (all) Sustenance, Lord of Power, Steadfast (for ever).
(Surah 51:57-58)
And call not, besides Allah, on another god. There is no god but He. Everything (that exists) will perish except His “own Face” (Presence). To Him belongs the Command, and to Him will ye (all) be brought back. (Surah 28:88)
He taught Adam of His words:
Then learnt Adam from his Lord words of inspiration, and his Lord turned towards him; for He is Oft-Returning, Most Merciful.
(Surah 2:37)
For to anything which We have willed, We but say the word, "Be", and it is. (Surah 16:40)
Unlike Jews and Christians who have no specific names for God Muslims are commanded to worship God alone and to mention His Names during worship as commanded by Him in His Book the Quran and to shun any other names which has been invented without His authority:
"Lord of the heavens and of the earth, and of all that is between them; so worship Him, and be constant and patient in His worship: know thou of any who is worthy of the same Name as He?" (Surah 19:65)
He said: "Punishment and wrath have already come upon you from your Lord: dispute ye with me over names which ye have devised - ye and your fathers, without authority from Allah? Then wait: I am amongst you, also waiting."
(Surah 7:71)
God whom the Muslims worship is never absent in term of place and in term of time He is ever presence and none can escape His authority and Judgment:
And verily, We shall recount their whole story with knowledge, for We were never absent (at any time or place). (Surah 7:7)
When My servants ask thee concerning Me, I am indeed close (to them): I listen to the prayer of every suppliant when he call on Me: Let them also, with a will, Listen to My call, and believe in Me: That they may walk in the right way.
(Surah 2:186)
The choice is yours to take salvation through Jesus the Son of God or through God only who is Allah “The One God”.
On the Day of Judgment all will be judged for the deeds which they have forwarded in this world and the true God will appear by the attributes as described in truth in His Holy Books and He will be presence as the ultimate Judge. The correct belief will come to pass.
In Christianity it is being propagated that Jesus taught that anyone who believes in Him "shall not come into judgment, but has passed from death into life" as stated in John 5:24
Verily, verily, I say unto you, He that heareth my word, and believeth on him that sent me, hath everlasting life, and shall not come into condemnation; but is passed from death unto life.
Christians therefore will conclude that those who have been "born again" by receiving Jesus Christ as Lord and Savior will be transformed into a heavenly state when Jesus Christ comes back again. All of these people, according to the apostle Paul, will answer for their Christian service and stewardship at the "judgment seat of Christ" at that time as stated in the following verses:
But why dost thou judge thy brother? Or why dost thou set at nought thy brother? for we shall all stand before the judgment seat of Christ. (Romans 14:10)
To whom ye forgive any thing, I forgive also: for if I forgave any thing, to whom I forgave it, for your sakes forgave I it in the person of Christ; (2 Corinthians 5:10)
None of these true believers, however, will face eternal condemnation at the Great White Throne, because Jesus Christ has already paid for their sins at Calvary (A hill outside ancient Jerusalem where Jesus was crucified).
"Everyone therefore who acknowledges me before others, I also will acknowledge before my Father in heaven; but whoever denies me before others, I also will deny before my Father in heaven." (Matthew 10:32-33)
Salvation is through the One God Allah is the only path.
On the contrary in Islam salvation belong to God alone as He is the One who can save and none can intercede except with His permission and He only accepts those who intercede for a good cause as stated in the following verses:
O ye who believe! Spend out of (the bounties) We have provided for you, before the Day comes when no bargaining (Will avail), nor friendship nor intercession. Those who reject Faith they are the wrong-doers. (Surah 2:254)
Whoever intercedes for a good purpose will receive his share of the reward but the intercession for an evil purpose only adds more to one's burden. God has control over all things. (Surah 4:85)
Allah promise the good in this world and the hereafter for believers
Whoever works righteousness, man or woman, and has Faith, verily, to him will We give a new Life, a life that is good and pure and We will bestow on such their reward according to the best of their actions. (Surah 16:97)
"He that works evil will not be requited but by the like thereof: and he that works a righteous deed - whether man or woman - and is a Believer- such will enter the Garden (of Bliss): Therein will they have abundance without measure.
(Surah 40:40)
Allah will deliver those who believe and work righteousness and abandon the evils ones on the Day of Judgment.
So, by thy Lord, without doubt, We shall gather them together, and (also) the Evil Ones (with them); then shall We bring them forth on their knees round about Hell; Then shall We certainly drag out from every sect all those who were worst in obstinate rebellion against (Allah) Most Gracious. And certainly We know best those who are most worthy of being burned therein. Not one of you but will pass over it: this is, with thy Lord, a Decree which must be accomplished. But We shall save those who guarded against evil, and We shall leave the wrong-doers therein, (humbled) to their knees. (Surah 19:68-72)
To be delivered one has to worship God alone and not to put partners to God whether it being a son or wife or other entities invented by human faculties. Allah says in the Quran:
Verily, this brotherhood of yours is a single brotherhood, and I am your Lord and Cherisher: therefore worship Me (and no other). (Surah 21:92)
Among His Signs are the Night and the Day, and the Sun and the Moon. Do not prostrate to the sun and the moon, but prostrate to Allah, Who created them, if it is Him ye wish to worship. (Surah 41:37)
Those to whom We have given the Book rejoice at what hath been revealed unto thee: but there are among the clans those who reject a part thereof. Say: "I am commanded to worship Allah, and not to join partners with Him. Unto Him do I call, and unto Him is my return." (Surah 13:36)
Allah makes it easy His path to salvation there is no necessity the intercession of “a middleman”. Allah is directly approachable:
If any one does a righteous deed, it ensures to the benefit of his soul; if he does evil, it works against (his own soul). In the end will ye (all) be brought back to your Lord. (Surah 45:15)
Say: "Verily my Lord enlarges and restricts the sustenance to such of his servants as He pleases: and nothing do ye spend in the least (in His cause) but He replaces it: for He is the Best of those who grant Sustenance. (Surah 34:39)
We shall set up scales of justice for the Day of Judgment, so that not a soul will be dealt with unjustly in the least, and if there be (no more than) the weight of a mustard seed, We will bring it (to account): and enough are We to take account. (Surah 21:47)
He that doeth good shall have ten times as much to his credit: He that doeth evil shall only be recompensed according to his evil: no wrong shall be done unto (any of) them. (Surah 6:160)
Only those who disbelieve and who reject with arrogance to His message in the Holy Books will be of those unfortunate in this world and more in the hereafter:
And your Lord says: "Call on Me; I will answer your (Prayer): but those who are too arrogant to worship Me will surely find themselves in Hell - in humiliation!" (Surah 40:60)
"And O ye in sin! Get ye apart this Day! "Did I not enjoin on you, O ye Children of Adam, that ye should not worship Satan; for that he was to you an enemy avowed? "And that ye should worship Me, (for that) this was the Straight Way? "But he did lead astray a great multitude of you. Did ye not, then, understand? (Surah 36:59-64)
Finally the Prophet Muhammad (Pbuh) was inspired by God to say to all human kind:
"I am but a man like yourselves, (but) the inspiration has come to me, that your Allah is one Allah: whoever expects to meet his Lord, let him work righteousness, and, in the worship of his Lord, admit no one as partner. (Surah 18:110)
ASAR
