And Samuel spoke unto all the house of Israel, saying, If you do return unto the LORD with all your hearts, then put away the foreign gods and Ashtaroth from among you, and prepare your hearts unto the LORD, and serve him only: and he will deliver you out of the hand of the Philistines.
Read Chapter 7
“However, Samuel said to the whole house of Israel, ‘If you are returning to the Lord with your whole heart, remove the foreign gods from your midst.’ ” This passage and whatever follows up to the statement that “he built there an altar to the Lord” shows in a figurative manner how the Lord taught in Judea, performed miracles, suffered, rose and ascended into heaven and sent the grace of the Holy Spirit, thus making not only the Jews but also the Gentiles partakers of his mercy. Therefore, after Eli had died and Samuel had assumed the priesthood, Samuel told the whole house of Israel to remove the foreign gods from their midst.
He said, “And prepare your hearts for the Lord and serve him alone, and he will deliver you from the hand of the Philistines.” The Lord, the author of a new priesthood which is manifested in the flesh according to the order of Melchizedek, teaches the whole house of Israel, that is, the church made up of those desiring to see God, to remove from themselves the traditions of the Pharisees. He teaches them not only to prepare works (a thing that the law also taught) but also to prepare their very hearts for serving the Lord alone. He said, “You have heard that it was said by the fathers … I, however say to you,” for in this way they would be able to be freed from all their enemies in the life to come. - "Four Books on 1 Samuel 1.7"