"When He is come, He will reprove the world of sin... because they believe not on Me" (John 16:8-9). Usually, when we think of conviction of sin we think of a strong feeling of guilt or remorse over things we have done. No doubt, feelings of remorse and guilt should come upon us when we have done wrong. But when the Lord tells us what true conviction of sin is, He says "of sin, because they believe not on Me." The sin of sins is to not trust in Christ for salvation. You have experienced Holy Spirit conviction when you see the wickedness of attempting to come into God's presence any other way than the way of Christ alone.