The most significant part of a chiasm is its middle. In the case of I Corinthians 10:1-2 the significant phrase is that this was a baptism. It was a baptism of water, the Red Sea, and of the Spirit in the Glory Cloud which was leading them to the Promised Land. Compare Matthew 3:16 and Romans 8:14.AFor I do not want you to be unaware, brethren, that our fathers were all under the cloud and all passed through the sea; (10:1)Band all were baptized into Moses (10:2a)A’in the cloud and in the sea; (10:2b)