John Wesley on Revelation 11:17

The Almighty - He who hath all things in his power as the only Governor of them. Who is, and who was - God is frequently styled, "He who is, and who was, and who is to come." but now he is actually come, the words, "who is to come," are, as it were, swallowed up. When it is said, We thank thee that thou hast taken thy great power, it is all one as, "We thank thee that thou art come." This whole thanksgiving is partly an enlargement on the two great points mentioned in the fifteenth verse; Rev 11:15 partly a summary of what is hereafter more distinctly related. Here it is mentioned, how the kingdom is the Lord's; afterwards, how it is the kingdom of his Christ. Thou hast taken thy great power - This is the beginning of what is done under the trumpet of the seventh angel. God has never ceased to use his power; but he has suffered his enemies to oppose it, which he will now suffer no more.