No, you don't. But let's consider what the word of God says; Jesus states in Matthew 28:19-20, "Go ye therefore, and teach all nations, baptizing them in the name of the Father, and of the Son, and of the Holy Ghost teaching them all things whatsoever I have commanded you"...note that Jesus' command to: "to teach new converts is given twice, once before baptizing them, and then again after baptizing them. This is logical and reasonable.