Augustine emphasised the supreme importance of love of God as a uniting and directive force for all human activity.
Without this, he insisted, the so-called pagan virtues were hollow. In spite of their spiritual unease (restlessness), Christian love, which is the centre of spiritual gravity, is drawing people ever onwards until they can find its repose in God, Who is the only real and supreme good. As Augustine wrote, "You have made us for yourself, O Lord, and our hearts are restless until they rest in You." (Confessions)
The only reason that love can distinguish between individuals is that a person is as he or she loves. In his On the Epistle of John, Augustine wrote, "Always as a person loves, so he is. Do you love the earth? Then you are of the earth. Do you love God? Then you are of God." Even though Augustine thus prioritises our love of God above our love of the earth, do not think that Augustine is interested solely in love of God.
Indeed, once when asked in which of these loves a person would best attempt to improve, he suggested that one should begin with whichever one was found to be the easier, for one would not improve much in either without improvement in the other also happening. Augustine could make that statement because of his belief that the love of neighbour and the love of God were in fact not two different loves but identical loves.
To Augustine love is not the indulgence of self; your love is what your behaviour shows to be of highest importance to you. He stressed this very much in his instruction to his priests at Hippo during the lengthy controversy with the Donatists, whose adherents locally outnumbered the people in his own church in Hippo.
He preached love against these theological opponents. While he hammered the Donatists' beliefs, he advised that as human beings and as Christians they were to be loved. He directed his priests, "Keep this in mind, my brothers; practice it and preach it with in a gentle manner that shall never fail. Love the persons you oppose, and kill only their lies. Rest on truth; defend it, but without cruelty. Pray for those whom you oppose; pray for them while you correct them."
If a person loves God he or she finds true liberty and wholeness. And if a person loves creatures without reference to the Creator, he or she loses insight and understanding. Sin is a perversion of love and as such is its own punishment.
"You do not know which others will be with God. You do not know how God has foreknown them... These people therefore who are not yet members of his Church are hidden neighbours of ours... Consequently, let us who do not know the future accept each and every person as a neighbour." (Second Homily on Psalm 25,2)