John Wesley: Optimist of Grace, by Henry H. Knight, is one of the best summaries of John Wesley’s theology that I have ever read (and it is, by far, the shortest). Here are a few excerpts:
Wesley’s vision of a new creation filled with the love of God is a fitting outcome of his theology. From 1725 on he was committed to holiness of heart and life as the content and goal of salvation; now, near the end of his life, he extended renewal in love from the hearts of humans to the entirety of creation. [Which means that all of creation will be redeemed/saved.] This was one of the last of the many insights Wesley gained throughout his life and ministry.
His fundamental insight, that governed all the rest, was that salvation is all about our renewal in love, our being restored to the image of God. Without this holiness of heart and life we are neither truly happy nor truly Christian. 
… Commenting on 1 John 4:19 (“We love him, because he first loved us”) Wesley wrote, “This is the sum of all religion, the genuine model of Christianity. None can say more: why should any one say less . . .”332 Wesley believed that this love of God will triumph in the end, and it is this same love that seeks to triumph even now, in every human heart. 
I’ve been thinking about restarting The Breakfast Club with this book. Let me know if you’re interested.
 Henry H. Knight III, John Wesley: Optimist of Grace (Eugene, Oregon: Cascade Books, 2018), 141.
2] Ibid., 145