This is an unconditional promise God makes. It's made without respect to Jacob's past unfaithfulness. God announces that He will be faithful to Jacob.
But Jacob's response isn't unconditional trust in God or God's promise. "If God will be with me and will watch over me on this journey I am taking and will give me food to eat and clothes to wear so that I return safely to my father’s household, then the Lord will be my God..." (vv.20-21) "IF...THEN..." "If God will do what I want Him to do," Jacob is saying, "then I'll believe in Him and worship Him."
I can be an "if...then" believer. God has claimed me as His own in Holy Baptism, sending His Holy Spirit to enable me to believe and call on Him through Jesus. But when I sense God calling me to have that tough conversation, to do something kind that will be inconvenient, to speak out for justice, to forgive as I've been forgiven, to love as I am loved, to spend time with someone even though I'd rather be doing something else, to reconnect with friends, or to tell people what God has done (and is doing) for me in Jesus, I break out into the "If thens."
If it's on my way.
If I can find the time.
If I see changes in the other person.
If I thought that it would do any good.
If I had any influence.
But I realize that since God doesn't put any strings on His promises to me, I can't put strings on the promises I make to Him. I am to live in response to His grace from moment to moment in all the moments of my life. Even the hard or inconvenient or seemingly futile ones.
God has bought me out of slavery to sin and death through the offering of God the Son, Jesus, on the cross. All who call on Jesus' name are daily being saved from sin, death, and futility.
Because I'm as human, flawed, and sinful as Jacob...and, like him, with a checkered past, I will only ever be able to keep my promises to God (or to others) with the help of God. "Without Me, you can do nothing," Jesus says (John 15:5). I've come to realize how literally true those words are!
And even when Jesus is helping me to do something worthwhile, I--me, my fears, my shortcomings, my imperfections, my selfishness--get in the way. (As Jesse Jackson famously said back in 1984, "Be patient with me; God isn't finished with me yet.") Right now, like the apostle Paul, we only see all that God has in mind for us as in a mirror dimly (or, a glass darkly).
But God's promises are solid. I pray that today, I'll be all-in for Him and not cave in to the temptation to say, "If God gives me what I want, then I'll follow Him or seek to do His will."
Because God has never said, "If you get your act together, Mark, then I will love and forgive you and give you life with Me," with the help of God, I won't tell Him, "If...then" today.
Make it so today, Lord, I pray.
Just a few thoughts.
[I'm the pastor of Living Water Lutheran Church in Centerville, Ohio.]