Leviticus 6:1-7 New International Version (NIV)

6 The Lord said to Moses: ² “If anyone sins and is unfaithful to the Lord by deceiving a neighbor about something entrusted to them or left in their care or about something stolen, or if they cheat their neighbor, ³ or if they find lost property and lie about it, or if they swear falsely about any such sin that people may commit— ⁴ when they sin in any of these ways and realize their guilt, they must return what they have stolen or taken by extortion, or what was entrusted to them, or the lost property they found, ⁵ or whatever it was they swore falsely about. They must make restitution in full, add a fifth of the value to it and give it all to the owner on the day they present their guilt offering. ⁶ And as a penalty they must bring to the priest, that is, to the Lord, their guilt offering, a ram from the flock, one without defect and of the proper value. ⁷ In this way the priest will make atonement for them before the Lord, and they will be forgiven for any of the things they did that made them guilty.”

Stealing and borrowing something from someone and not returning it are the same. This is sin against God and the other person. If you have gotten something deceitfully, confess your sin, apologize to the owner, and return what was stolen with interest.