Psalm 138 began with a commitment to acknowledge the Lord as God, even in the face of other gods with more immediate appeal. And it closes with an affirmation of God's sovereignty. This sounds like a remote theological concept, but when things aren't going as I planned—even when everything is messed up—it is deeply reassuring to know that God's will will not be thwarted, that
the Lord will fulfill his purpose for me; your steadfast love, O Lord, endures forever. Do not forsake the work of your hands.
✙ Ps. 138:8 ✙
If I need further biblical proof of this, then all I need to do is turn to Romans 8. The final twelve verses [28-39] of that chapter are an elaboration on this same promise, as well as an answer to the prayer that God not forsake a child of God:
We know that all things work together for good for those who love God, who are called according to his purpose. For those whom he foreknew he also predestined to be conformed to the image of his Son, in order that he might be the firstborn within a large family. And those whom he predestined he also called; and those whom he called he also justified; and those whom he justified he also glorified. What then are we to say about these things? If God is for us, who is against us? He who did not withhold his own Son, but gave him up for all of us, will he not with him also give us everything else? Who will bring any charge against God’s elect? It is God who justifies. Who is to condemn? It is Christ Jesus, who died, yes, who was raised, who is at the right hand of God, who indeed intercedes for us. Who will separate us from the love of Christ? Will hardship, or distress, or persecution, or famine, or nakedness, or peril, or sword? As it is written, 'For your sake we are being killed all day long; we are accounted as sheep to be slaughtered.' No, in all these things we are more than conquerors through him who loved us. For I am convinced that neither death, nor life, nor angels, nor rulers, nor things present, nor things to come, nor powers, nor height, nor depth, nor anything else in all creation, will be able to separate us from the love of God in Christ Jesus our Lord.
Thank you, Lord, that there has never been a time when I have been without you, and that your will for my life can never be defeated. As you will not forsake me, grant that, by your grace, I may keep to the path that leads to you; in the Name of him who showed me that path, and who taught me to pray...