It is said that the number of about 100 different gospels [which were recognized at that time] were reduced to four at a Council in Nicaea. Is this true, and if so, how can we be sure that today’s gospels are authentic?
Answer: There have been two ecumenical Councils in Nicaea (Iznik), the first in 325, the second in 787. Neither of these Councils debated the issue of the canon of the Holy Scriptures. With regard to the gospels of the New Testament, the Church had already agreed on the authenticity of the 4 pieces of writing which today form part of the New Testament during the course of the first two centuries. There was and still is a certain number of gospels which are called the apocrypha, but there are far fewer than 100 of them. These are gospels which were not excluded from the authentically revealed scriptures at the time.
Modern critical Biblical researchers agree that none of the apocrypha can claim a higher degree of authenticity than the four which form part of the New Testament. It goes without saying that the term apocryphal does not imply that everything these gospels tell is inaccurate, inauthentic and contrary to orthodox faith. C.f. F.L. Cross (ed.), “The Oxford Dictionary of the Christian Church”. Oxford: OUP, 1990. Art. APOCRYPHA, The; APOCRYPHAL, NEW TESTMANT, The; CANON OF SCRIPTURE.