For one to have true, spiritual joy, he must love, and in order to love he must believe. People do not believe, so they do not love, they do not sacrifice themselves, and they have no joy. If they believed – they would love, they
would sacrifice themselves to others and they would have had joy… A man who knows what is gratitude he is pleased with everything. He thinks about what God gives him every day and he rejoices in everything.
Venerable Paisios the Athonite