Ask the Lord for a sign, to open or close a door. Sin is doing the opposite of what we believe the Holy Spirit wants us to do. The Holy Spirit would never ask us to do something that is inconsistent with God's Word. For example, the Holy Spirit would never ask us to steal food because Jesus said we should not steal. God's glory reflects His perfect character which we often fail to live up to.
Sin is a failure to live with godly character and motives.
For you were like sheep going astray, but now you have returned to the Shepherd and Overseer of your souls. Sin is wandering away from the Lord's presence and trying to get what we want by ourselves. Let him who walks in the dark, who has no light, trust in the name of the LORD and rely on his God. But now, all you who light fires and provide yourselves with flaming torches, go, walk in the light of your fires and of the torches you have set ablaze. Let him who walks in the dark rely on His God.