What does God say about growing in love?

It is true that He taught no new thing in his commandments and the substance of the same thought is taught by all prophets of any people—neither can any spirit bring a newer or truer thought to (hu)man than the one incomprehensible, immeasurable thought of God's love to all that He hath created, and that you should love him and love to do his will that you may grow ever to be more like him.

As you acquire of His nature, so may you acquire of His knowledge, and thus of His power.