A question that may regularly be asked is that why are there so many religions in the world? It is true that there are many, but there is the possibility that some or maybe even all of the major religions around the world began from the same source: a true Prophet or a Messenger from God - Prophets being those who recieved teachings, guidance and prophecies, and Messengers being those who in addition to being Prophets of God, also received a book which was meant to be preserved.
Only 'Islam', the last revealed way of life, has survived intact and without change. All messages which went before it were changed. After these Prophets or Messengers passed away, the people often forgot or altered the teachings, advice and examples of their Prophets over many generations until they were so mixed up in their beliefs that it was no longer a true way of life from God. Thus a man-made 'religion' was born.
For example, Hinduism is a complicated mixture of myths, legends, spiritual philosophy and strange rituals. No true Prophet ever taught that women should be burned alive in their husband's funeral fire, that it was good to become a begger and sleep on a bed of nails etc. At the same time, Hinduism teaches that good is better than evil and that the soul of a person lives on after the body has died, although they added the strange idea of re-incarnation to the concept. So some of the real teaching survived, but much has been twisted and transformed.
So basically every nation in the past recieved Prophets from Allah. Later generations lost, corrupted or changed these teachings, resulting in many of the different religious systems that we have today!
CHRISTIANITY - THE BEGINNING
The common view among leading Christian scholars is that the origins of modern day Christianity is based upon the theosophy of Paul of Tarsus who never met Jesus (PBUH), and up until his conversion, he had been a bitter enemy of any one who accepted the teaching of Jesus (PBUH). Paul (or Saul as he was known then) was at the forefront of a campaign directed against the followers of Jesus (PBUH) and was notorious for his persecution of them.
During a journey to Damascus, Paul claimed to have had a vision of Jesus (PBUH). Paul states in Acts 26:16 that Jesus (PBUH) said: "Now get up and stand on your feet. I have appeared to you to appoint you as a servant and as a witness of what you have seen of me and what I will show you". Thus Paul claimed to have a unique access to Jesus (PBUH) via revelation, an honour which even the closest of the followers of Jesus (PBUH), the disciples, were denied! This is all no doubt hard to believe!
After the famous conversion of Saul the Jew to Paul the Christian, Paul "straight away preached Christ in the synagogues, that he (Jesus) was the Son of God." (Acts 9:20). He claimed that he was a messenger of God and an apostle of the Prophet Jesus (PBUH)! He changed the true teachings of Jesus (PBUH)! Thus the Christian community that followed his teaching became established, and organised themselves into the Pauline Church, which was later to become known as the Roman Catholic Church.
Even the simplest of commandments that Jesus (PBUH) adhered to have become obsolesecent in the World of Christendom. For example, most Christians today do not adhere to any dietry regulations, even though Jesus (PBUH) was a Jew and therefore would not have eaten the flesh of swine or meat that was not slaughtered according to the Jewish sacrificial method.
This is of particular significance when viewed in light of statements attributed to Jesus (PBUH) in the Gospel according to Matthew 5:17, "Think not that I am come to destroy the Law (Torah) or the Prophets: I am come not to destroy but to fulfil." and in 5:19, "Whosoever therefore shall break one of the least commandments and shall teach men so, he shall be called the least in the Kingdom of Heaven: but whosoever shall obey and teach them, the same shall be called great in the Kingdom of Heaven." So according to this verse, Jesus (PBUH) would not have broken the Jewish Law and anyone who does so was of a low rank in the sight of God. So, surely Paul who broke many laws, and paved the way for countless innovations must fall into this category!
Another example of the loss of the basic commands among Christians is that of circumcision of the male infant. This command, according to the Bible, was given to the Prophet Abraham (PBUH) as part of his covenant and the circumcision of Jesus (PBUH) is mentioned in the Gospel according to Luke 2:21, "When eight days were accomplished for the circumcision of the child, his name was called Jesus...".
Moving on, Jesus (PBUH) did not tell his followers to worship him but to worship only Allah (i.e. God). As the Quran states, regarding the day of Judgement, when Allah will question Jesus (PBUH):-
"And behold! Allah will say: "O Jesus the son of Mary! Did you say to men, "Worship me and my mother as two gods besides Allah?" He will say, "Glory to You! Never could I say what I have no right (to say)" (Al-Ma'ida 5:116)
Every time a Muslim prays, they recite the following from Al-Fatiha (The Opening Chapter - the first chapter of the Quran):-
"You (alone) do we worship and from You (alone) do we seek help" (Al-Fatihah 1:4)
Therefore, we should only worship Allah. God created Jesus (PBUH), the son of Mary, without a father. His was a virgin birth, a miracle and a sign from Allah. But the Quran reminds humankind that Allah also created Adam (PBUH) without a father or a mother:-
"The example of Jesus, before Allah is like that of Adam. He created him from dust, then told him, "Be!" and he was: (This is) the truth from your Lord, so do not be of those who doubt" (Al-Imran 3:59- 60).
Jesus (PBUH) quoted in the Gospel according to Luke 4:8 as reaffirming pure monotheism, "It is written in the scripture: "Worship the Lord your God and Serve Him Only", as the Quran also says (as Jesus (PBUH) having said):-
"Verily Allah is my Lord and your Lord. So worship Him (Alone). That is the Straight Path." (Maryam 19:36).
The Quran corrects the Christians claim that Jesus (PBUH) was the son of God and that he deserves human worship by logical arguement:-
"Christ the son of Mary was no more than a Messenger; many were the Messengers that passed away before him. His mother was a woman of truth. They had both to eat their (daily) food. See how Allah doth make His Signs clear to them; yet see in what ways they are deluded away from the truth!" (Al-Ma'ida 5:75).
Thus, the statement "they both ate food" shows that despite the miraculous birth of Jesus (PBUH), he was only a human being like ourselves who required food, drink, sleep etc. The biggest sin that one can commit, is to associate partners with Allah, being so immense that it is the only unforgivable sin. The Quran says:-
"No son did Allah beget, nor is there any god along with Him. (if there had been many gods), then each god would have taken away what he had created, and some would have tried to overcome others! Glorified be Allah above all that they attribute to Him!" (Al-Muminun 23:91)
"It is not befitting to (the majesty of) Allah that He should beget a son. Glory be to Him! when He determines a matter, He only says to it, "Be", and it is." (Maryam 19:35).
Yet we find Christians who claim that Jesus (PBUH) is the son of God, and even some who say that he is God! The gravity of the insult of attributing a son or partner to Allah is so immense that Allah describes it in the response of the heavens, the earth and the mountains:-
"Indeed ye have put forth a thing most monstrous! At it the skies are about to burst, the earth to split asunder, and the mountains to fall down in utter ruin, That they attributed a son to the Most Gracious. For it is not consonant with the majesty of the Most Gracious that He should beget a son." (Maryam 19:89-92).
Regarding this unforgivable sin, the Quran states:-
"Allah forgiveth not that partners should be set up with Him; but He forgiveth anything else, to whom he pleaseth; to set up partners with Allah is to devise a sin most heinous indeed." (An-Nisaa 4:48)
By informing humankind about the gravest sin and the reason for its gravity, humans are given the chance to rid themselves of this sin. They may invoke Allah's mercy and carefully avoid the unforgivable crime of worshipping others besides Allah. If this is sincerely done they deserve to recieve Allah's forgiveness on the Day of Judgement.
THE APPEARANCE OF THE BIBLE
In 325CE the Roman emperor, Constantine, called for a conference of all the Christians. He ordered them to bring their books and writings with them. He then commanded them to agree on something and then left them alone to argue.
The majority of the Christian representatives were from Europe and believed that Jesus (PBUH), was God and God's son and that God was divided up into three parts called a 'Trinity' (three-in-one). The minority, who were from Africa and the Middle East, believed that Jesus (PBUH) was a Prophet and not God.
Well, the majority was able to get their ideas accepted by Constantine. They put these letters and writings together in a book which they called a 'Bible' (latin word meaning 'Book') and ordered all other writings to be burned. African and Middle Eastern Christians went home in disgust.
Ever since, European Christians have believed in Trinity theories and notions of God having a son. The New Testament then is a collection of notes, letters to friends, biographies and fantasy stories. The Christians made up the term old and new Testament and they say Allah is done with the Jews and now saves only Christians. Obviously the Jews, who reject Jesus (PBUH), do not agree. Their Old Testament was put together in about the year 100 and is a collection of Jewish writings spanning thousands of years about their tribe, culture and thoughts.
So to conclude here, the problem with these two religions is that Allah sent Prophets to all nations with the 'universal' message and no one has the right to change that. The Holy Quran on the other hand, is the last book of Allah and has not been changed since it was revealed, contains no contradictions or errors and its authenticity is proved by exactly these facts, and by the fact that it contains many signs and miracles. It is the true words of Allah, completely unchanged and untampered with, and which could not have possibly been written by any human being!