Saint Augustine is a scholastic philosopher and one of the fathers of the Church among his teachings is: Love and do what you want. This phrase within the Christian theology has a very important reason, the theologians like Thomas Aquinas and St. Augustine base justice in love. In other words, where there is no love for work, it can not be justice, this is an idea that is strongly expressed by theologians. Aristotle, on the other hand, base justice on the desire for happiness. It is at this point that there is a difference between Greek philosophy and the scholastics, the relationship of love with virtue.
It is with this affirmation that St. Augustine seems to take some ideas expressed by the Apostle Paul, about grace and justification, about the slavery of the sin and the freedom of love.
When we love good we are exempt from the law (commanments) and the virtue of justice. What does this mean?
The justice and the commandments are the settings of the "natural man". In the logic of the natural man helping others is a moral duty. The moral duty is what characterizes the natural man, but the spiritual man, the Christic man is free of the moral duty. In the doctrine of the Kingdom of God helping others is not a duty, the help is because our neighbor is our brother.
The help is because our filiality with God and the entire creation. The spiritual man by filiality with God lives the gifts received from the divine. Recall that the purpose of the gifts is the common good and communion, not the selfish happiness.
Good love overcomes all moral duty and frees us from the law and all the principles of justice. "The other matters".
We are called to be complete as God, as the tree in spring buds, blossoms and bears fruit, we are called to the good love, the love for all the creation. The natural man is an incomplete man, a selfish man, is really a children's personality. Sin and moral duty limit us. We are called to the love and freedom of God.