It is not all made up!! Jesus Christ is God. Jesus is the Son of God.
KJV said here,
Matthew 1:1 The book of the generation of Jesus Christ, the son of David, the son of Abraham.
Matthew 1:21 And she shall bring forth a son, and thou shalt call his name JESUS: for he shall save his people from their sins.
Matthew 1:23 Behold, a virgin shall be with child, and shall bring forth a son, and they shall call his name Emmanuel, which being interpreted is, God with us. Emmanuel means God is with us!
John 14:6 Jesus saith unto him, I am the way, the truth, and the life: no man cometh unto the Father, but by me.
John 3:16 For God so loved the world, that he gave his only begotten Son, that whosoever believeth in him should not perish, but have everlasting life.