O: To truly commit a sin, consciously and deliberately, means one is choosing to turn away from God. If one continues down that path, he will never know God.
A: I think John is saying here that those who commit sin purposefully are not with God. I would like to think that if we sin accidentally, realize it, and then repent, we could still be with God. But to deliberately commit a sin is like slapping God in the face.
P: Lord, I don't even want to "accidentally" sin against you. Please help me stay aware in all situations of my actions and responses to others so that I do not sin against you. I want to know you, God. Amen.