"Whoever does not love does not know God, for God is love."–1 John 4.8
"God is often styled holy, righteous, wise; but not holiness, righteousness, or wisdom in the abstract, as he is said to be love; intimating that this is his darling, his reigning attribute, the attribute that sheds an amiable glory on all his other perfections."–John Wesley, Notes on the New Testament, commenting on 1 John 4.8.
The belief that love, not sovereignty, not power, not holiness, not justice, etc. lies at the very heart of Wesley's theology.