Yesterday I noted some Reformed teaching concerning the kingdom of God – from around 1700, in England and in Holland, the Reformed language was the same: God is king over all things, which is his kingdom of power. He also rules the church in a specific, saving way, which is his kingdom of grace (now) and glory (heaven). Both Watson and a Brakel used this language (even Ursinus did before them).
Lutherans use the exact same language: this is another area of harmony between confessional Lutherans and the confessional Reformed. Here’s Q/A 212 from Luther’s small catechism (this section is appended on to Luther’s own small catechism as a sort of expansion or explanation).
“What is the kingdom of God?”
“The kingdom of God is His ruling as king over the whole universe (kingdom of power), the church on earth (kingdom of grace), and the church and angels in heaven (kingdom of glory).”
I also noticed that both the Reformed and Lutherans used some of the same verses to explain this two kingdoms doctrine.