This psalm is not as provincial as it might seem on the surface. If I’m serving God and you are serving God, it’s possible we’ll still be knocking up against each other, but highly unlikely. God chose King David of Israel to rule the nation He chose as His earthly means to revelation. This psalm assumes that David and Israel are engaged in that mission faithfully. It doesn’t assume they never sin, but it also doesn’t chase the rabbit of when and where David as king or Israel as a whole sinned against God.
When David and Israel were faithful, no nation was permitted to stand in their way. So far as we can determine, this is historically accurate. David didn’t fail in war against external enemies. It’s not as if no one sought terms of peace with him. It wasn’t hard at all. The nations weren’t required to join the Covenant of Moses, but could not oppose it. David made peace with plenty of pagan rulers whose religions were of no concern to him. His were not wars of religious conquest, but a matter of securing the opportunity for Israel to proceed with their religion and the mission that came with it. That mission was to demonstrate the truth so that those whom God called would be drawn to to Him.
The parabolic implications are obvious. David was a type for Jesus. Those who faithfully serve Jesus have nothing to fear from this world. Whatever authority secular powers exercise cannot hinder the gospel message for long. When our mission reflects the genuine calling of gospel, the Lord opens doors to the message and protects the mission. Obviously, our measure for faithfulness is far more subtle than merely observing Moses. Jesus made much greater demands than Moses, not so much in terms of performance, but in terms of personal commitment. Christ is our King with none of David’s weaknesses. Whatever problems we face are not from sin in our King, but either our own sin or something we may never understand. More importantly, whatever problems we face are our Lord’s problems; our mission is to remain faithful. The possibility of moral failure is a dark and threatening cloud on the horizon, just a reminder.