This question comes up from time to time in our church. Whether from someone who was baptized as an infant where they don’t remember it, or from someone who was baptized as a child because they felt like they should or because they were genuinely a follower of Jesus.
Here’s a simple response from a fellow Acts 29 pastor that we have adopted:
If you were not a true Christian when you got baptized and you have (since then) trusted in Jesus alone for salvation, let’s baptize you again. But if you were a true Christian when you got baptized but just didn’t understand it fully, we would recommend that you don’t get re-baptized.
The reason we land there is because baptism will always become more significant for us as we learn and grow in the gospel. Sometimes, we don’t fully grasp our baptism until years after it happened. That fact actually highlights the beauty of Jesus saving us even when we didn’t fully understand every single detail. But thankfully there is a Sacrament for Christians to participate in even after they grow into a deeper knowledge and love for the gospel – the Lord’s Supper. The Lord’s Supper is where we can continually celebrate the gospel at work in our lives.
So in essence, we see baptism as something that allows the believer to profess initial faith in Jesus (after genuine conversion), but the Lord’s Supper as something that allows the believer to continue to profess faith and celebrate the gospel.