Am I trusting in something I did or in the gospel for my salvation?
You should not trust in something you did; you should depend on a solid faith in the gospel wherein the power of God has been exercised. Self-examination asks whether you are relying on your own works or on the gospel. When the Spirit indwells, He leads and guides, confirming true salvation.
Les explains that assurance is not gained by working harder but by self-examination in the light of Scripture. He points to the question of whether you are depending on something you have done or on a solid faith in the Gospel wherein the power of God has been exercised. When that happens, the Holy Spirit comes into your life and leads, guides, and directs, so you do not have to live by rules and regulations. Believers are led by the Spirit of God, which is one indication of true salvation. Les also cites evidences such as a hunger for the Word, enjoying God's people, and enjoying prayer time.