Augustine of Hippo

But how can we love God, if we love the world? He prepareth us therefore to be inhabited by charity. There are two loves: of the world, and of God: if the love of the world inhabit, there is no way for the love of God to enter in: let the love of the world make way, and the love of God inhabit; let the better have place. Thou lovedst the world: love not the world: when thou hast emptied thine heart of earthly love, thou shall drink in love Divine: and thenceforth beginneth charity to inhabit thee, from which can nothing of evil proceed. Hear ye therefore his words, how he goes to work in the manner of one that makes a clearance. He comes upon the hearts of men as a field that he would occupy: but in what state does he find it? If he finds a wood, he roots it up; if he finds the field cleared, he plants it. He would plant a tree there, charity. And what is the wood he would root up? Love of the world. Hear him, the rooter up of the wood! "Love not the world," (for this comes next,) "neither the things that are in the world; if any man love the world, the love of the Father is not in him."

Ye have heard that "if any man love the world, the love of the Father is not in him." Let not any say in his heart that this is false, brethren: God saith it; by the Apostle the Holy Ghost hath spoken; nothing more true: "If any man love the world, the love of the Father is not in him." Wouldest thou have the Father's love, that thou mayest be joint-heir with the Son? Love not the world. Shut out the evil love of the world, that thou mayest be filled with the love of God. Thou art a vessel; but as yet thou art full. Pour out what thou hast, that thou mayest receive what thou hast not. Certainly, our brethren are now born again of water and of the Spirit: we also some years ago were born again of water and of the Spirit. Good is it for us that we love not the world, lest the sacraments remain in us unto damnation, not as means of strengthening unto salvation. That which strengthens unto salvation is, to have the root of charity, to have the "power of godliness," not "the form" only. Good is the form, holy the form: but what avails the form, if it hold not the root? The branch that is cut off, is it not cast into the fire? Have the form, but in the root. But in what way are ye rooted so that ye be not rooted up? By holding charity, as saith the Apostle Paul, "rooted and grounded in charity." How shall charity be rooted there, amid the overgrown wilderness of the love of the world? Make clear riddance of the woods. A mighty seed ye are about to put in: let there not be that in the field which shall choke the seed. These are the uprooting words which he hath said: "Love not the world, neither the things that are in the world. If any man love the world, the love of the Father is not in him."