Psalm 56:12-13 (JDV)
Psalm 56:12 I am obligated by vows to you, God; I will make my thank offerings to you.
Psalm 56:13 You see, you rescued me from death, my own feet from stumbling, to walk before God in the light of life.
The Christian feels the obligation to worship out of gratitude for the rescue. God accomplished our rescue from the penalty of death that we deserve. Our rescue sets our feet back on the right path, a path of walking before God. We are under this obligation not in order to be rescued, because neither our worship nor our walk can accomplish that. No, we are obligated to worship and walk in his light because he has rescued us by his grace.
Lord, thank you for the grace by which we stand, walk and worship.