How do you know when someone loves you? Is there a specific formula or list of things? Personally, the love of another person is more ‘real’ to me when I see that they really know me. Deep love comes from knowing someone well.
Paul had friends he called ‘partners in the gospel’, like teammates on the same mission. He prayed a lot for them, and he prayed that their love (for God and for others) would be the kind of love that knows and understands.
To grow in knowledge of God, set aside time to read the Bible. To grow in knowledge of people, go talk to them! Take an interest in their story, their struggles, their hopes. To love more deeply, learn more deeply.