He was against the christians on those days...
He was against the christians on those days, and after a revelation in a dream, he became christian, and he became the father of todays' christianity. Nobody asked him those days: Where have you been my son when Jesus was on the cross? Why do you claim that you can now expand, explain, and defend the religion which you fought for a few years? My point is that: He became the base of christianity and the source of revelation. Everything, then, came through him.
Several rules and theology of christianity, all came through his sentences which were not in the original religion at the beginning. How many sentences, you think, caused christians to deviate from their true roots? There is a person named as Abu Hurairah whose history I will bring after a while.
This man says himself: Narrated Abu Huraira: There is none among the companions of the Prophet who has narrated more Hadiths than I except 'Abdallah bin Amr (bin al-'As) who used to write them and I never did the same. All nine volumns of Sahih Bukhari contains 7068 traditions. From these traditions, about 1100 traditions are narrated from this man, in other words, 15.56% of the whole traditions in Sahih Bukhari (almost 1/6).
(I will soon give you the number of traditions narrated by Abu Hurairah in Sahih Muslim.) As I showed on "Abu Huraira or Loui Pasteur", he contradicted himself as well as science. The following hadith is another one where he clearly narrates a hadith which is not in accordance with what Aisha and Umm Salamh narrate. If we accept that Aisha and Umm Salamh were in the house of the prophet more than any other wives, we can easily see the problem here.
{This is in page 81, in a section titled as: Is a fasting person gets up in the morning in the state of Janaba (will his fast be valid?) This hadith is translated by the translator ONLY up to the end of the first paragraph. He then stopped translating. However, the arabic text is still there. The rest is my own translation. If you do not want to trust me, I suggest you refer to the arabic text. In addition, I will bring you more sources for the explanation and translation I made.
Narrated Aisha and Umm Salam: At times Allah Apostle (may peace be upon him) used to get up in the morning in the state of Janaba after having sexual relations with his wives. He would then take a bath and fast. Marwan said to Abdu-arrahman ibn Hareth: Swear to God that by (hearing) this, Abu Huraira will scream. At this time, Marwan was in Madinah.