"Whoever believes that Jesus is the Christ is born of God…"
What is belief?
If I say I believe in Donald Trump but the pattern of my life is continued support for Nancy, do I truly believe?
If I say I believe in Jesus Christ but the pattern of my life is continual living my own way and not His Way, do I truly believe?
Jesus preached in His first sermon, "Repent…" and the people tried to throw Him off a cliff. Why? Because, the Truth is a "rock of offense" to those who are perishing.
"Why do you call me 'Lord, Lord,' and not do what I tell you?"