When Solomon became old, his wives shifted his allegiance to other gods; he was not wholeheartedly devoted to the Lord his God, as his father David had been.
[1 Kgs 11:4 NET]
The trouble was all in Solomon’s heart. It is the heart that needs watching and keeping with all diligence. A “perfect” heart does not mean a sinless heart, but a heart wholly devoted in its aim and motive to God and His service.
Solomon had a corner in his heart for the Lord, and then other corners for the gods of all the other nations. The Saviour’s words are: “Ye cannot serve God and mammon.”
We need to be on our guard against Solomonian religion. There is plenty of it. It abhors the preaching of the stern truths of god’s word about sin and penalty, and about holiness. It sends well–nigh everybody to heaven, and regards hell as a mere fable. It calls strict Christians “puritanic” or “strait–laced.” It calls great sins “escapades,” and finds no use for such psalms as the fifty–first.
It is not hard to see in this verse, however, which of the two kinds of religion pleases God best, and which leads to the best end.