The only begotten son of God. My belief was first instilled when considering the incredible consistency of character in the described Jesus Christ in the New Testament. Hence, resonance with my own understanding of what people are like and what mythology looks like, told me this material was a record of someone neither ordinary nor mythological. Given the attraction of the person JC, it was natural to believe in the resurrection. Complexity theory, chaos theory, probability theory - all of the sciences seem to blare the existence of information as the center of existence.
Information presupposes an informer.
The Word of God made flesh. I find the message delivered compelling in my own heart. I don't think that the question is very amenable to argument, CS Lewis though, makes a good job of it. Very God of very God and very man of very man. As being God he shares all the attributes of the Biblical definition of the God of the Bible.