Solomon had an understanding heart in order to hear and act according God’s word, but did not have the will to obey what God was showing him.

I considered all that my hands had done and the toil I had expended in doing it, and behold, all was vanity and a striving after wind, and there was nothing to be gained under the sun. (Ecclesiastes 2:11)

Do not merely listen to the word, and so deceive yourselves. Do what it says … the man who looks into the perfect law that gives freedom, and continues to do this, not forgetting what he has heard, but doing it – this man will be blessed in what he does. (James 1:22, 25)

At times, we feel like we need to help God, but in reality, God does not need our help, but simply wants our obedience; this was Solomon’s mistake.

So the kingdom was established in the hand of Solomon. (1 Kings 2:46)

Solomon made a marriage alliance with Pharaoh king of Egypt. (1 Kings 3:1)

The king must not acquire many horses for himself or cause the people to return to Egypt in order to acquire many horses, since the Lord has said to you, “You shall never return that way again.” And he shall not acquire many wives for himself, lest his heart turn away, not shall be acquire for himself excessive silver and gold.
And when he sits on the throne of his kingdom, he shall write for himself in a book a copy of this law, approved by the Levitical priests. And it shall be with him, and he shall read in it all the days of his life, that he may learn to fear the Lord his God by keeping all the words of this law and these statues, and doing them, that his heart may not be lifted up above his brothers, and that he may not turn aside from the commandment, either to the right hand or the left, so that he may continue long in his kingdom, he and his children, in Israel. (Deuteronomy 17:16-20)

King Solomon’s wrong assumptions led him into three major sins against God and God’s word.

Solomon did not trust in the protection of God.

And Solomon gathered together chariots and horsemen. He had 1400 chariots and 12,000 horsemen, whom he stationed in the chariot cities and with the king in Jerusalem… Solomon’s import of horses was from Egypt… (1 Kings 10:26-28)

Woe to those who go down to Egypt for help, and rely on horses, who trust in chariots because they are many and in horsemen because they are very strong, but do not look to the Holy One of Israel, or consult the Lord. (Isaiah 31:1)

Some trust in chariots and some in horses, but we trust in the name of the Lord our God. (Psalm 20:7)

“Cursed is the one who trusts in man, and makes flesh his strength, whose heart turns away from the Lord, He is like a shrub in the desert, and shall not see any good come. He shall dwell in the parched places of the wilderness, in and uninhabited land. (Jeremiah 17:5-6)

Solomon did not trust in the promise of God.

King Solomon drafted labor to build the house of the Lord and his own house and the Millo and the wall of Jerusalem and Hazor and Megiddo and Gezer… and Lower Beth-horon and Baalath and Tamar in the wilderness, in the land of Judah. King Solomon built a fleet of ships at Ezion-geber, which is near Eloth on the shore of the Red Sea. (I Kings 9:15-19, 26)

Behold, a son shall be born to you who shall be a man of rest. I will give him rest from all his surrounding enemies. For his name shall be Solomon, and I will give peace and quiet to Israel in his days. (1 Chronicles 22:9-10)

Solomon did not trust in God’s power.

Now King Solomon loved many foreign women along with the daughter of Pharaoh: Moabite, Ammonite, Edomite, Sidonian, and the Hittite women, from the nations concerning which the Lord had said to the people of Israel, “You shall not enter into marriage with them, neither shall they with you, for surely they will turn away your heart after their gods.” Solomon club to these in love. He had 700 wives, and 300 concubines. And the wives turned away his heart. (1 Kings 11:1-3)

Trust in the Lord with all your heart, and do not lean on your own understanding… (Proverbs 3:5)

I also gathered for myself silver and gold and the treasure of kings… (Ecclesiastes 2:8)

Although Solomon was wise and understanding, the root of his downfall was his lack of love and meditation on God’s word.

How can a young man keep his way pure? By guarding it according to your word. With my whole heart I seek you; let me not wander from your commandments! I have stored up your word in my heart, that I might not sin against you. (Psalm 119:9-11)

By faith Moses, when he was grown up, refused to be called the son of Pharaoh’s daughter, choosing rather to be mistreated with the people of God than to enjoy the fleeting pleasures of sin. (Hebrews 11:24-25)

Falling in love with God’s word leads to obedience in the Lord, which ultimately begins by having faith in the Gospel of Christ.