Tell me what you are led to believe in the following:
But these are written, that ye might believe that Jesus is the Christ, the Son of God; and that believing ye might have life through his name.
Pretty much John 20:31, and I John 5:13 are basically the same for me, in that the words used as "believe, and believing", are not of man's confidence in acquisition, but rather God's influence in and upon faith.
John is writing these things, yes, but it is not in merely accepting his writings that gives life, but rather the power of God that gives life.
Jesus is the Father's Son, and the Expression of the Father to the Son, and Son to the Father, is the Holy Spirit(which we most easily associate with Love), thus we know Father, Son and Holy Spirit as the Three Persons known as God.