"The growth of love evinces its truth. If I see the almond tree bud and flourish, I know there is life in the root. Paint will not grow; a hypocrite, who is but a picture, will not grow. But where we see love to God increasing and growing larger, as Elijah's cloud, we may conclude it is true and genuine."
"God is the most adequate and complete object of our love. All the excellencies that lie scattered in the creatures, are united in Him. He is wisdom, beauty, love, yea, the very essence of goodness. There is nothing in God can cause a loathing; the creature sooner surfeits than satisfies, but there are fresh beauties sparkling forth in God. The more we enjoy of Him, the more we are ravished with delight. There is nothing in God to deaden our affections or quench our love; no infirmity, no deformity, such as usually weaken and cool love. There is that excellence in God, which may not only invite, but command our love. If there were more angels in heaven than there are, and all those glorious seraphim had an immense flame of love burning in their breasts to eternity, yet could they not love God equivalently to that infinite perfection and transcendence of goodness which is in Him. Surely then here is enough to induce us to love God -- we cannot spend our love upon a better object."
Thomas Watson All Things For Good