What is then the perfection of which man is capable while he dwells in a corruptible body? It is the complying with that kind command, ‘My son, give me thy heart.’ It is he ‘loving the Lord; his God with all his heart, and with all his soul, and with all his mind.’ This is the sum of Christian perfection: It is all comprised in that one word, Love. The first branch of it is the love of God: And as he that loves God loves his brother also, it is inseparably connected with the second: ‘Thou shalt love thy neighbor as thyself:’ Thou shalt love every man as thy own soul, as Christ loved us. ‘On these two commandments hang all the Law and the Prophets: These contain the whole of Christian perfection.
Many more John Wesley quotes on the topic of Christian Perfection can be found here: THE NATURE OF CHRISTIAN PERFECTION. And here’s a link that will take you to the Table of Contents of John Wesley’s own compilation of his teachings on this topic: A Plain Account of Christian Perfection.