Judas committed suicide almost immediately after Christ's crucifixion.So the chances of him writing a gospel is very less.But there is overwhelming evidence that all the other disciples wrote gospels.Do not forget that Christ expressly instructed everyone to spread his Word before His departure.They knew that writing about Christ's life and teachings is the best method to spread His Word. Since many of his followers understood the historic importance of Christ's momentous life and His path-breaking teachings,they proceeded to write it down.Hence,there was a lot of material available to the early church fathers,when they proceeded to compile the Bible.They selectively included those works which highlighted the positive aspects of Christ's life and diligently avoided(or edited) those works which included both positive and negative aspects of his life. It is clear that they wanted to emphasize the divinity of Christ and discourage looking at Christ as a human being.Hence the gospels of Philip,Thomas etc.were not included in the Bible.But these and other unknown works resurrected 50 years back in the form of Coptic scrolls(found in Egypt)and the Dead Sea Scrolls ,giving a better pic.
