No New Testament fact can be taught in the abstract. In one way or another Christ came to fulfill all of the Old Testament prophecies and types. The meaning to us is determined by how the inspired writers interpreted the types such as the flood. We do not have to worry about future floods or crossing of the Red Sea. These were physical types.
Baptism is the spiritual antitype or fulfullment of the type.
It is not real sharp thinking to make all fulfilled types mean exactly to what the type or prophecy pictured. In the same way, the ark was the time and place where God saved Noah and his family and restored the earth. Baptism is not the work of our own hands. Those who reject baptism often go through life with the Calvinistic doubt as to whether God has predestinated them for salvation. Therefore, they seek signs through ceremonial legalism.