“I am sending you to them to open their eyes and turn them from darkness to light, and from the power of Satan to God, so that they may receive forgiveness of sins and a place among those who are sanctified by faith in me.” (Acts 26:17,18)
Jesus’ words tell us what is actually going on when someone becomes a Christian.
It’s basically a change of allegiance. There are two opposing kingdoms in the universe: the power of Satan (which is darkness) and the power of God (which is light), and every person in the world is in either the one kingdom or the other. Now Satan has a strong grip on his domain and doesn’t want to give up any of his subjects. So evangelism is part of the spiritual battle that we are fighting against the forces of evil. That’s why we find it so difficult to evangelise! Warfare is dangerous, it’s hard, it demands sacrifices. Most normal people – and especially me – would much rather opt out and live a peaceful, easy life. And evangelism often feels like an uphill struggle. Every conversion is a small victory – which is why baptisms are such a cause for celebration.
Now why is Satan’s kingdom called the power of darkness? Because, as Paul says in II Corinthians, “he has blinded the minds of unbelievers, so that they cannot see the light of the gospel.” (II Corinthians 4:4) In other words, unbelievers aren’t being deliberately awkward or stubborn; they simply can’t see or understand the truth. They are blind because, spiritually speaking, they have grown up in the dark. And they like living in the darkness; it feels normal to them, it feels comfortable. We have to shine like lights into their darkness (Philippians 2:15,16), showing them that there is an alternative. And we do this by demonstrating in what we say and in what we do that Jesus is our Lord. By living differently, living under His Lordship. For when you move from the kingdom of Satan to the Kingdom of God, and start calling Jesus ‘Lord’, there are certain inevitable consequences.
The first one mentioned in this verse is forgiveness of sins. What Jesus seems to be saying is that we receive forgiveness from Him simply as a result of putting ourselves under His authority. Do we have to pray a special prayer to ask God to forgive our sins? That’s what we usually encourage someone to do if they say they want to become a Christian, but although it may be helpful I don’t think it’s essential. What is absolutely essential is to let Jesus take charge of your life. Then we get forgiven, whether we specifically ask or not. If, as Paul says in Romans, you “declare with your mouth that ‘Jesus is Lord’, and believe in you heart that God raised Him from the dead, you will be saved.” (Romans 10:9) If Jesus is your Lord, then you are ‘sanctified by faith’.
The second consequence is membership of God’s Church – and by that I don’t mean having your name on the electoral roll, I mean being part of the family of God, a brother or sister of everyone else who is sanctified by faith in Jesus. We don’t just enter into new life, we also join a new community – the company of Jesus’ people, a foretaste of God’s Kingdom on earth.