Charles H. Spurgeon on Psalms 81:15

The haters of the Lord should have submitted themselves unto him. Though the submission would have been false and flattering, yet the enemies of Israel would have been so humiliated that they would have hastened to make terms with the favoured tribes. Our enemies become abashed and cowardly when we, with resolution, walk carefully with the Lord. It is in God's power to keep the fiercest in check, and he will do so if we have a filial fear, a pious awe of him. But their time should have endured for ever. The people would have been firmly established, and their prosperity would have been stable. Nothing confirms a state or a church like holiness. If we be firm in obedience we shall be firm in happiness. Righteousness establishes, sin ruins.