Why do you think the four that we have today are in the Bible and these others are not? God did not give the church a handsomely bound book and say "Get this straight: these four are THE gospels and only these four; just so you humans won't mess up, I'm giving you this book all nicely printed and bound -- what is in this is what is revealed and inspired, no more no less!" Similarly there is no evidence that Jesus gave his followers a list and said "Here is a list of books I want in the Bible." The Bible, one must remember, is a book intended for humans, for believers, for the Church -- it is a book that is to be used. It is the Church itself which "decides" which books it accepts as revealed and it is the Church which selects which works to include in and reject from its Bible. Those works which a church includes as revealed form what is called a "canon".