After explaining what idolatry is he gives an example:
Take an instance that occurs almost every day: A person who has been long involved in the world, surrounded and fatigued with abundance of business, having at length acquired an easy fortune, disengages himself from all business, and retires into the country–to be happy. Happy in what? Why, in taking his ease…
Happy in altering, enlarging, rebuilding, or at least decorating, the old mansion-house he has purchased; and likewise in improving everything about it: the stables, out-houses, grounds. But, mean time, whetre does God come in? No where at all. He did not think about him. He no more thought of the King of heaven, than of the king of France. God is not in his plan. The knowledge and love of God are entirely out of the question. Therefore, this whole scheme of happiness in retirement is idolatry, from beginning to end.
From a sermon titled Spiritual Idolatry in The Works of John Wesley Vols. 6, p. 432