46If you love those who love you, what reward will you get? Do not even tax collectors do the same?
47And if you greet only your brothers, what are you doing more than others? Do not even Gentiles do the same?
48Be perfect, therefore, as your heavenly Father is perfect. Matthew 5:46-48
The complete, perfect love that the nicest of worldly people don't have is unconditional love, particularly for their enemies. The defining characteristic of God's love is that it is unconditional. It is given apart from consideration of whether or not someone is pleasing to you, or deserves it, or has earned it. You'll only experience this kind of ability to love when filled with the Holy Spirit. That's why it's an experience that belongs exclusively to the Christian and why it is the signifying mark of the mature child of God.