1 Kings 3:2
Only the people sacrificed in high places, because there was no house built unto the name of the LORD, until those days. Only the people sacrificed in high places, because there was no house built unto the name of the LORD, until those days.
The people were sacrificing in high places because no house had yet been built for the name of the Lord. This was the setting of Solomon's early reign, when he himself also offered sacrifices at Gibeon, the great high place. It exposes a failure on Solomon's part, for though he knew the temple would take much time to build, before building the house of the Lord or the walls about Jerusalem he should have prepared a temporary place of worship for God's people. Instead, by his own example of going to the high places to offer sacrifice, he encouraged the people to do the same, which he should not have done. By sacrificing in a place not made sacred by the presence of the Lord but dedicated to the worship of idols, he lessened in the minds of the people the repulsion with which they should have regarded the horrible practices of idolaters. This mingling of the sacred and the profane was the first step that led him to suppose the Lord was not so particular about the worship of His people, and by it he was educating himself to depart still further from God and His work, until little by little his heathen wives led him to make altars on which to sacrifice to their gods.