One of the misconceptions about being a Christian is that we are goody two-shoes. People, including Christians themselves, think that once they believe on Jesus, they can become good people overnight.
How I wish that were true. It is true that believing on Jesus justifies us. This means that the punishment we deserve for sin we have (and for future sin we may commit) is paid for completely by Jesus. We can stand before God and be counted as righteous. That is what we call justification (see for example Romans 4:22–5:1).
That doesn't mean we gain perfection. That will only come with our resurrected bodies. In the meantime, together with God's help, we work on the process of sanctification. Romans 6:1–14 tells us that we need to fight to keep sin away from our bodies. Verse 12 says, "Do not let sin reign in your mortal bodies." Reign is the keyword here. The word reign conjures up images of rulers and slaves, kings and soldiers. Make no mistake, the process of sanctification is not a walk in the park. It is a daily battle of surrendering our body and mind to God, in order that we can be armed to fight sin in every area of our lives. Like the character of Christian in John Bunyan's Pilgrim's Progress, we are on a journey, heading towards God's heavenly city. Galatians 5:16–24 reminds us to walk by the Spirit and we will not gratify the desires of the flesh. That to me is a clear indication that though we have been justified, the old sin nature still lurks beneath the surface. It is no surprise then, when it rears its ugly head and we by natural instinct obey its lusts. We are by no means perfect. But we are to use the Spirit and kill our sinful inclinations and keep marching on towards God.
This process we will never finish. We will always have more sin inside us to kill. But the promise of God is that "he who began a good work in you will bring it to completion at the day of Jesus Christ." (Philippians 1:6). We will see perfection on the day of Jesus Christ. What a promise. So having faith and being justified is only the beginning. That work is God's alone. Sanctification is God's Spirit working in us as we direct our lives toward God himself. Justification brings direction, not perfection.
