The Explicit “Why” and “How” of Being a Disciple of Jesus

The Apostle John (Jesus’ earthly best friend) wrote:
“We know that we have come to know [Jesus] if we keep his commands. Whoever says, “I know him,” but does not do what he commands is a liar, and the truth is not in that person. But if anyone obeys his word, love for God is truly made complete in them. This is how we know we are in him: Whoever claims to live in him must live as Jesus did” (1 John 2:3-6, NIV).
Why was John so adamant that if we do not obey Jesus’ commands and follow His example, then we are not really saved?
To answer that question, let me give you my background.