Paul concludes his great chapter on the resurrection of the dead by commanding believers to be “steadfast, unmoveable, always abounding in the work of the Lord” (1 Cor. 15:58). Psalm 15 concludes with a conceptually parallel statement: “He that doeth these things shall never be moved” (15:5b).
The parallel idea in both of these passages suggests that Psalm 15 provides us with inspired instruction about how we can be immovable, as God commands:
15:1 <A Psalm of David.> LORD, who shall abide in thy tabernacle? who shall dwell in thy holy hill?
2 He that walketh uprightly, and worketh righteousness, and speaketh the truth in his heart.
3 He that backbiteth not with his tongue, nor doeth evil to his neighbour, nor taketh up a reproach against his neighbour.
4 In whose eyes a vile person is contemned; but he honoureth them that fear the LORD. He that sweareth to his own hurt, and changeth not.
5 He that putteth not out his money to usury, nor taketh reward against the innocent. He that doeth these things shall never be moved.
The teaching of Psalm 15 can be helpfully organized in the following way.
In general, to be immovable, we must walk uprightly and work righteousness. These general statements pertain to the entirety of our lives, teaching us that we should be blameless people who live righteously and fulfill our obligations to God and man.
Positively, we must speak the truth in our hearts. The truthfulness of whatever we say either to ourselves or to others is crucial to our being upright, as God commands.
We must also “treat or think of [vile people] with contempt” (Webster’s definition of contemn), but honor those who fear God. An upright person thus must not honor evil people, and he must not fail to honor godly people.
In addition, we must keep the promises that we make, even if hurts us to do so. Any oaths that we make must be fulfilled.
Negatively, we must not backbite with our tongues. As upright people, we thus must not slander anyone.
We also must not do evil to our neighbors or take up a reproach against them. Our dealings with everyone we encounter, therefore, must be upright, not harming anyone in action or speech.
Furthermore, we must not go back on our promises. Our “yes” should mean that we do what we have said we would, and our “no” should mean that we do not do what we say we will not do.
We also must not lend our money with usury. If we choose to lend money to people, we should not “take advantage of those who must borrow” (BKC: OT, 803).
Moreover, we must not accept a bribe against an innocent person. We must steadfastly refuse the efforts of any person who would bribe us so that we would pervert the justice that innocent people are due.
God commands us to be upright people who are immovable in our living for Him all our days. He will grace us to do so as we strive in the power of the Spirit to follow the teaching of 1 Corinthians 15 and Psalm 15.