The prophet Isaiah wrote about the Messiah, Jesus Christ: “Surely he took up our pain and bore our suffering, yet we considered him punished by God, stricken by him, and afflicted. But he was pierced for our transgressions, he was crushed for our iniquities; the punishment that brought us peace was on him, and by his wounds we are healed. We all, like sheep, have gone astray, each of us has turned to our own way; and the LORD has laid on him the iniquity of us all” (Isaiah 53: 4-6). Jesus endured the punishment of the world’s sins as the innocent Lamb of God.
Romans 8:1-2 states: “Therefore, there is now no condemnation for those who are in Christ Jesus, because through Christ Jesus the law of the Spirit who gives life has set you free from the law of sin and death.” When the Holy Spirit creates saving faith in Jesus in our hearts, we enjoy the benefit of the Lamb of God’s work: we have peace with God through the forgiveness of sins.
When Christians sin, God does not punish them. He has already punished Jesus in their place. What God may do is exercise discipline Christians (cf. Hebrews 12:4-12). Discipline is far different from punishment. The motive behind discipline is love and it has the good of people in mind. So, no, God does not punish Christians when they do wrong.
The “Light for our path” column in the September 2018 issue of Forward in Christ will address a question that is similar to yours.