We always pray for you, that our God may make you worthy of his calling and may fulfill every resolve for good and every work of faith by his power, so that the name of our Lord Jesus may be glorified in you, and you in him, according to the grace of our God and the Lord Jesus Christ. (2 Thessalonians 1:11–12)
Grace is not only God’s disposition to do good for us when we don’t deserve it — we call this “undeserved favor”; God’s grace is also a power from God that acts in our lives and makes good things happen in us and for us — which we also don’t deserve.
Paul said that we fulfill our resolves for good “by his power” (verse 11). And then he adds at the end of verse 12, “according to the grace of our God and the Lord Jesus Christ.” The power that actually works in our lives to make Christ-exalting obedience possible is an exertion of the grace of God.
You can see this also in 1 Corinthians 15:10:
By the grace of God I am what I am, and his grace toward me was not in vain. On the contrary, I worked harder than any of them, though it was not I, but the grace of God that is with me.
So, grace is an active, present, transformative, obedience-enabling power.
Therefore, this grace, which moves in power from God to you at a point in time, is both past and future. It has already done something for you or in you and therefore is past. And it is about to do something in you and for you, and so it is future — both five seconds from now and five million years from now.
God’s grace is ever cascading over the waterfall of the present from the inexhaustible river of grace coming to us from the future into the ever-increasing reservoir of grace in the past. In the next five minutes, you will receive sustaining grace flowing to you from the future — in this you trust; and you will accumulate another five minutes’ worth of grace in the reservoir of the past — for this you give thanks.