I have a friend who, when someone in our men’s groups says something like, “I’m going to try to memorize scripture” or whatever, he responds with a smile and says, “‘I’m going to try’ is the least form of commitment.”
It is certainly not a promise. A promise is good, but a guarantee is even better.
In Galatians, perhaps his earliest letter written, he speaks about the Genesis 15 covenant with Abraham and the animals cut in half, by emphasizing God’s promise to Abraham:
So also Abraham “believed God, and it was credited to him as righteousness.”
The promises were spoken to Abraham and to his seed.
For if the inheritance depends on the law, then it no longer depends on the promise; but God in his grace gave it to Abraham through a promise. (Gal. 3:6, 16, and 18)
Then a few years later, now beginning to see God’s faithful promises as much more, he shifts from promises to guarantees:
For no matter how many promises God has made, they are “Yes” in Christ. And so through him the “Amen” is spoken by us to the glory of God … He anointed us, set his seal of ownership on us, and put his Spirit in our hearts as a deposit, guaranteeing what is to come. (1 Cor. 1:20-22)
Then a few more years later, now after many years living with Jesus’ promised Holy Spirit, Paul again emphasizes God’s guarantee, because he now sees it as indeed a rock-solid guarantee:
Therefore, the promise comes by faith, so that it may be by grace and may be guaranteed to all Abraham’s offspring—not only to those who are of the law but also to those who have the faith of Abraham. He is the father of us all. (Rom. 4:16)
And finally, while sitting in Rome under arrest, when most people in his position would say God had absolutely let him down, Paul again emphasizes God’s guarantee:
And you also were included in Christ when you heard the message of truth, the gospel of your salvation. When you believed, you were marked in him with a seal, the promised Holy Spirit, who is a deposit, guaranteeing our inheritance until the redemption of those who are God’s possession—to the praise of his glory. (Eph. 1:13-14)
May you, my friend, learn to live with the confidence inspired by your Father’s guarantee, that when you are born again, you are sealed in Christ in glory. And nothing you ever do will change that.