What shall I render to the Lord for all his benefits to me? I will lift up the cup of salvation and call on the name of the Lord, I will pay my vows to the Lord. (Psalm 116:12–14)
The very use of the language “rendering to God for all his benefits to me” makes me nervous. Payback can so easily imply that grace is like a mortgage. It’s really generous, but you have to pay it back.
Paul said in Acts 17:25, God is not “served by human hands, as though he needed anything, since he himself gives to all mankind life and breath and everything.” In other words, you can’t give anything to God or do anything for God that he hasn’t first given to you and done for you.
You see this again 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 none of our work can ever be a payment to God, because the very work is another gift from God. With every deed we do for God we go deeper into debt to grace.
So in Psalm 116 what keeps the paying of vows free from the dangers of being treated like a debt payment is that the “payment” is, in reality, not an ordinary payment, but another act of receiving which magnifies the ongoing grace of God. It does not magnify our resourcefulness.
The psalmist’s answer to his own question, “What shall I render to the Lord for all his benefits?” is, “I will lift up the cup of salvation and call on the name of the Lord.” In other words, I call on the Lord to fill the cup. To pay back the Lord means to go on receiving from the Lord so that the Lord’s inexhaustible goodness will be magnified.
Lifting up the cup of salvation signifies taking the Lord’s satisfying salvation in hand and drinking it and expecting more. We know this because of the next phrase: “I will . . . call on the name of the Lord.” I will call for more help. What shall I render to God for graciously answering my call? Answer: I shall call again. I will render to God the praise and the tribute that he is never in need of me, but is always overflowing with benefits when I need him (which I always do).
Then the psalmist says, in the third place, “I will pay my vows to the Lord.” But how will they be paid? They will be paid by holding up the cup of salvation and by calling on the Lord. That is, they will be paid by faith in the promise that more grace — all-sufficient grace — is always on the way.