How does God expect His people to live? This is an old question, but the answer isn’t any less relevant. King David asked the same thing, a long time ago, in a galaxy far, far away:

Psalm 15:1 O LORD, who shall sojourn in thy tent?
Who shall dwell on thy holy hill?

His opening line is rhetorical. David knows the answer. But, the question itself is worth mulling over for a moment or two. Who can live in God’s tent? Who has a place in His house? Who has, as it were, a seat at His family dinner table? As Israelites and the Gentile proselytes came to Jerusalem three times per year, and began the climb up the “holy hill” to God’s city, who among them had an eternal home with the Lord?

David is not asking for the identity of all the people who belong to God; he wants to know what kind of people belong to God. What do God’s people act like? What motivates their heart and infuses their soul? To quote the great philosopher Jerry McGuire, what “completes” them?

At this point, the reader has to make a decision – is David explaining how a man becomes a child of God, or is he describing how a child of God will want to live? That is, is his answer prescriptive (e.g. do this, and become a child of God) or descriptive (e.g. a child of God will want to do this)?

The Scripture teaches us David is being descriptive. Man cannot earn his way to salvation, or else Christ wouldn’t have had to come in the first place (Galatians 2:21).

Psalm 15:2 He who walks blamelessly, and does what is right,
and speaks truth from his heart;

David locates the desire for righteous and holy behavior in the heart. Outward conformity is meaningless and cheap. We all know people who are frauds. They speak and act one way, but we know it’s an act – because we’ve seen the mask slip.

No; a man who belongs to God will want to walk blamelessly, and he’ll honestly try to do it. He won’t do it to earn salvation or buy favor from God; he’ll do it because he loves the Lord and wants to do what He says (Deuteronomy 6:4; Mark 12:28-30). This last bit is critical – an ungodly man can be morally upright. There are plenty of decent, “moral people” who have good manners. David isn’t talking about this.

To borrow a legal phrase, God doesn’t recognize behavior that is the fruit of a poisonous tree. A child of God will love God, and this love produces a real desire for loving obedience. A child of Satan (i.e. somebody who is not a Christian; see Ephesians 2:1-4) has no love for God, and therefore his actions don’t flow from that love. The motivations are different, therefore the moral weights of each action are different, too.

Consider this:

• A co-worker named Cynthia knows you like Lee Child’s novels featuring Jack Reacher, so she snags an old paperback from a used bookstore and gives it to you for a birthday present.
• Your wife gives you the same birthday present later that day, when you return home

You received presents from both women; identical presents. Which one carries more weight? The one from your wife, of course. Why? Because the relationship is clearly different. You’re in a covenant relationship with your wife; whereas Cynthia is the nice 65-yr old grandmother from work.

In a similar way, God weighs the believer’s actions differently than the unbeliever’ actions. In fact, in God’s case, the unbeliever’s actions have no moral value whatsoever, because they’re not being done out of loving obedience.

Psalm 15:3 who does not slander with his tongue,
and does no evil to his friend,
nor takes up a reproach against his neighbor;

It’s fascinating how David’s descriptive proofs for a child of God focus so much on action. There is much to be commended about a focus on internal motivation as a check against rote legalism. After all, we don’t want to be hypocrites, going through the external motions while our hearts are harder than stone.

But, David (and God!) don’t let us off so easy. The other side of the ditch is just as treacherous. It’s so easy to excuse external conformity with pious appeals to “the heart,” isn’t it? A man claims to be a Christian, but has lived like a reprobate for years. “Oh,” he says, “I love God! I want to serve Him, honest!” At some point, every Christian needs to be honest with himself – where is the fruit?

David expects there to be fruit. Period. A godly man doesn’t slander, doesn’t betray his friend and doesn’t slander and reproach his neighbor. In other words, he seeks to be holy, because God is holy (Leviticus 19:2; 1 Peter 1:14-15).

Psalm 15:4 in whose eyes a reprobate is despised,
but who honors those who fear the LORD;
who swears to his own hurt and does not change;

This bit is particularly interesting. A godly man will despise a reprobate (i.e. a vile person, a flagrant sinner). This is somebody who is nominally part of the Old Covenant community, but lives in complete rebellion against God. David says Israelites should despise this person; have contempt for him. In contrast, a godly woman will honor those who reverently fear the Lord.

What’s the purpose? It’s likely about shame. There is something to be said for peer pressure. But, doesn’t this concept go completely against our modern church culture? We prefer to love people to death, even when they deserve contempt, rebuke, or censure. In short, we’re wimps.

To be sure, David isn’t saying we should hate everybody who sins; we’re not on witch hunts for non-conformists. But, if you have somebody who (1) is a professing believer, (2) who is a reprobate; a vile and habitual rebel, and (3) he refuses to try to conform to God’s word, (4) then you need to take action – once all lesser means have failed. The man is hardened in his perversity and his rebellion is deliberate and calculated.

Part of this action is for the rest of the covenant community to have open contempt for the offender, and shower honor on those who honestly love the Lord.

Psalm 15:5 who does not put out his money at interest,
and does not take a bribe against the innocent.

He who does these things shall never be moved.

Isn’t is fascinating how sin so often revolves around money? In my experience in law enforcement and regulatory investigations, people do wrong for three reasons – money, sex and power. It doesn’t matter whether you’re a Christian; these three temptations are universal. Godly people will fight against these urges; thus we have David’s warnings against shady business practices. To be sure, sometimes we’ll lose against these urges. But, the general trajectory of our personal lives should be trending towards more Christlikeness, not less.

This is a short little psalm; five whole verses. Yet, it sums up an entire theology of the Christian life. Who will dwell with the Lord, and dwell in His tent? The one who proves his love for God by concrete action. What kind of action? All kinds; but this psalm gives us a good start.

This isn’t an ethic that an unbeliever can have, because only a believer’s actions flow from his love for the Lord. This was one of Jesus’ points in the Sermon on the Mount. It’s David’s point here, too.