"And the period that Solomon reigned in Jerusalem over all Israel was forty years."
--I Kings 11:42
The reign of King Solomon is a rather bittersweet one. Here he was, the wisest man who had ever lived, ruling over a powerful, wealthy nation at peace, yet the evidence that we glean from Scripture is that his forty-year reign was the prelude to disaster. As Solomon breathes his last breath, the kingdom is poised on the brink of rebellion because of heavy taxation and forced labor (see I Kings 9:20-22; 12:1-5); his heir, Rehoboam, is proud and listens only to his foolish friends (see I Kings 12:6-11); and God has been shunted aside to share glory with a menagerie of other deities (see what happened in Israel immediately after his reign; I Kings 12:25-33).
The Bible provides us both sides of the coin of Solomon's time on the throne of Israel. He presided over Israel's Golden Age and the building of the Temple and a grand palace for the royal family (see I Kings 4:20-8:66). The Queen of Sheba and countless others visited Jerusalem to gaze on the wonders collected there by the king and to hear his wisdom firsthand (see I Kings 4:29-34; 10:1-13). Scripture informs us that gold and silver were as common in Israel's capital as baser metals were elsewhere (I Kings 10:14-23; II Chronicles 9:27). Solomon was so strong and the nations around were so weak that no one dared disturb the peace of the time (except at the very end of his reign; I Kings 11:14-40).
But the underside of the coin is far darker. Though Solomon had been humble as a young man, asking God for understanding so that he could properly rule and judge his people, his pride soon led him to disobedience. He began to flout the instructions given by God through Moses to Israel's kings (Deuteronomy 17:14-20). He made alliances with foreign nations, particularly Egypt, marrying hundreds of domestic and foreign princesses to cement these ties (I Kings 11:1-3). Of course, these women brought their own gods and goddesses to worship, and it was not long before Solomon was honoring their wishes to have various shrines and "high places" built to house their idols (see I Kings 11:4-8).
As usually happens, when the people saw that Solomon had compromised with idolatry, they followed suit, visiting the ancient groves and hilltop altars that had lain unused but not unforgotten. With few exceptions, subsequent kings either neglected God's command to destroy these high places or made half-hearted efforts. Solomon's reign set an unfortunate standard for most of the kings of Judah who followed him, and the people sank deeper into lifestyles contrary to the law of God.
The number forty is frequently a biblical indication of testing. Solomon received forty years from God to see if he would follow His ways or not. The book of Ecclesiastes indicates that, perhaps at the end of his life, Solomon made an effort to repent--or at least he realized that, in the end, it is a person's chief duty to fear God and keep His commandments (Ecclesiastes 12:13). We really do not know if he passed or failed his test, but we can learn a great lesson from the forty years of his wonderful, terrible reign.