"600 years after christ argument"

If the above infographic is to hard to read, then use the text below:

First of all why does the amount of time matter anyway? God can send revelation anytime he wants. It’s not up to us to question God’s decisions and decrees. The reason why God decided to send revelation to Muhammad peace be upon him in the 7th century is because God is all wise and knew that time in particular was the perfect time to send him. Also we could ask the Christians, “Why did God wait 400 years after Malachi to send Jesus?” 

Secondly just because something is earlier that doesn’t automatically and necessarily make it true and something coming later doesn’t automatically and necessarily make it false. When Christians use the 600 years argument they’re implying that since Christianity is earlier than Islam therefore it’s true. This is a very fallacious argument. By this logic Hinduism is true and the Hindu scriptures are more trustworthy than the New Testament because they are much earlier. Also we Muslims believe that Islam was the religion since the beginning of time so we can argue that Christianity came later. The 600 years argument assumes Islam never existed prior to the 7th century but we Muslims don’t believe that Islam started in the 7th century

Thirdly if Christians argue "The Quran came 600 years later, so it can’t be trusted to tell us the life of Jesus” then the proper response to expose the hypocrisy of this argument is to say:

“Why do you trust the book of Genesis to tell you about the life and history of Adam and Eve, Cain and Abel, Noah, Abraham, Lot, Ishmael, Issac, Jacob, Joseph or even the creation story of the universe if Moses came hundreds and thousands of years after all those events and people?”

If the Christians respond by saying, “Moses was a true prophet receiving  revelations from God” then we can just say “Muhammad peace be upon him is a true prophet receiving revelation from Allah, so he can narrate the stories of the previous prophets and events. It doesn’t matter how long he came after those people and events. If he’s proven to be a true prophet, then the time period should not matter.”