Although there is an evident distinction between love of God, love of neighbor, and love of self, a marvelous bond nevertheless does exist among the three, so that each is found in all, and all in each. None of them can be possessed without all, and when one wavers they all diminish. Someone who does not love his neighbor or God does not love himself, and someone who does not love his neighbor as himself does not love himself. Furthermore, someone who does not love his neighbor is proven not to love God. For ‘how can a person who does not love the brother he sees love God whom he does not see?’ These three loves are engendered by one another, nourished by one another, and fanned into flame by one another. Then they are all brought to perfection together.
Aelred of Rievaulx
The Mirror of Charity: 3.2.3,5; CF 17:223-224.