Ephesians tells us that we were dead in our transgressions. Most of the time, we act as though we are without sin or that we are better than some other people. It is important to realize that all sins are considered the same in the eyes of God. In our own eyes, we may be perfect but God sees all our imperfections.
Numbers shows us that time and time again, the Israelites forgot that God had come through for them. They kept complaining and their ingratitude hurt God. He decided to punish them, but in His great mercy, He directed Moses to lift up a bronze snake that required the Israelites to look up to it and be saved. It required a step of faith. Today Jesus has also been lifted up and God invites us to look up to Jesus and be saved.
Many of us think that it is our efforts that will save us. We work in His vineyard so that we will be saved, but Jesus wants us to work in His vineyard because we are saved. If we accept Jesus, He will bring us into his freedom and light.