We must remember that there's a battle that will rage in our soul until the day we die. Age and maturity don't conquer the flesh. Only the Spirit can win that battle. The Holy Spirit is released to do His work when we make the right choices. The moment we are faced with the lust of the flesh, we must choose that very instant to trust in the Holy Spirit for His victory.
Victory is always a daily choice - a moment by moment decision.
It's walking one step at a time by faith. He slew wild animals by faith. He defeated every enemy by the power of God. Yet, when he became king, there was a tendency to walk in a spirit of independence. Before his being crowned as king, he walked in humble dependence upon God.