Pope Gregory I

There are in truth three states of the converted: the beginning, the middle, and the perfection. In the beginning they experience the charms of sweetness; in the middle the contests of temptation; and in the end the fullness of perfection.

The proof of love is in the works. Where love exists, it works great things. But when it ceases to act, it ceases to exist.

There is more joy in heaven over a converted sinner than over a righteous person standing firm. A leader in battle has more love for a soldier who returns after fleeing, and who valiantly pursues the enemy, than for one who never turned back, but who never acted valiantly either. A farmer has greater love for land which bears fruitfully, after he has cleared it of thorns, than for land which never had thorns but which never yielded a fruitful harvest.