Help with witnessing efforts

I have been discussing religion with one of my coworkers a lot lately. He is the son of a Baptist pastor and is very knowledgeable. Today we got on the topic of what is different with our religions and there were a lot more than I originally thought. The four I really noticed were Baptism, the Lord's Supper, forgiveness, and fellowship. What are verses that I can use to show that Baptism creates faith, gives us forgiveness and salvation, and more importantly is not something that we do for God, but something God does for us? Also the same with the Lord's Supper: we get forgiveness of sins and salvation from it, but I believe the issue with this would be tied to the fact that we believe that the wine is both wine and blood and the bread is both bread and Jesus' body. What are some passages for this as well? He also said that only God can forgive. I don't know how to even address this topic with him, but I know it will come up. And the final one is where do we find the OK to have the rules we have about fellowship without looking like we are better than other Christians? I just would like to be prepared for my discussion with my coworker and I'm glad to do it. I just need some extra help. Thank you very much for your help!

We will not find a passage in the Bible that states specifically and succinctly: “Baptism creates faith.” We know that baptism is a faith-working act on God’s part by looking at several Bible passages and seeing how they relate to baptism. The Bible explains that people enjoy the forgiveness of sins and eternal life by God’s grace through faith in Jesus Christ his Son (Ephesians 2:8; Romans 3:28). The Bible states that baptism gives people those very blessings of life and forgiveness (Acts 2:38; 22:16; Ephesians 5:26; Titus 3:5-7; 1 Peter 3:21). Baptism gives those blessings because of the powerful word of God that is attached to the water. Since the Bible teaches that we enjoy salvation only through faith in Christ, and since the Bible teaches that baptism saves us and washes away our sins, we can rightfully say that baptism creates the faith that connects us to Jesus and brings into our lives all the blessings he won by his holy life, sacrificial death and glorious resurrection.

Matthew 26:26-28, 1 Corinthians 10:16 and 1 Corinthians 11:27 teach clearly that the reception of the Lord’s Supper involves bread and wine, and the Lord’s body and blood.

Matthew 18:15-20 and John 20:21-23 teach that God has given his Church the right and authority to forgive sins. Individually, we forgive others (Matthew 6:12; Colossians 3:13). When our pastors announce forgiveness in a worship service, they exercise the Keys on behalf of the congregation which has called them to do exactly that.

When it comes to what the Bible teaches about fellowship principles, let me refer you to an appropriate section of This We Believe, a statement of belief of our church body. I’m taking this approach to your last question because the subject of fellowship involves an understanding of the holy Christian church and visible churches. That section of This We Believe will give you appropriate Bible passages and accurate explanations on the subjects.

God bless your witnessing efforts!