Here is a closing illustration. I was in the ancient city of Philippi years ago when the local guide took some of us aside to show us the remains of an outdoor baptistery that had just been discovered. She commented that she couldn’t understand why the baptisteries in that area were round. Then she remarked, “Of course most of the graves and tombs from this time period were also round.”
I was able to tell her immediately why the ancient baptismal pools were round. I told her to remember the graves and then remember that baptism is a burial into the death of Jesus Christ. She had no difficulty grasping this truth and probably included this explanation in comments from that time on.