Mormonism asserts that Jesus was "a" Son of God, but not the "only" Son of God. That Lucifer is our spirit brother, and that Christ is our elder brother.
This video explores the Biblical evidences for Jesus being the only Son of God, and exaclty who the Bible alone, proclaims Him to be. He alone is the Son of God. This video will show you part of the overwhelming amount of evidence that the Bible alone enjoys.
The Case For Christ from JD Pilgrim on Vimeo.