^3:19 `Those whom I love, I reprove and discipline; be zealous therefore, and repent.

Those whom I LOVE, I REPROVE and DISCIPLINE;

The unwanted and unloved seldom have anyone around to discipline them. Thus we should be thankful that God is around to discipline us. John 14:19-21 says we are loved by God and He will disclose Himself to us. So if we are sons of God, then as a Father He disciplines us (Hebrews 12:4-13 and Proverbs 3:12). The "trying us" is for our growth to bring us to a place of abundance according to Psalm 66:8-15. We are to judge ourselves, and if we judge rightly then the Lord disciplines us (1 Corinthians 11:28-32).

be ZEALOUS therefore, and

A zealous person is NOT lukewarm, they are on FIRE! (1 Corinthians 15:58).

REPENT.

The very last thing an unbeliever wants to do is REPENT. The very last thing a believer wants to do is REPENT. Why?

It leads to exposure ("nakedness" in the previous verse 18) as to who you really are. BUT repentance has its good points!