In God's economy it is only possible to be in one state at a time. Thus, in Numbers 3, God explains that He is trading the Levites for the firstborn of Israel because it is not possible to have two firstborns. Similarly in John 3 Y'shua explains the Nicodemus that he is either born again or he is not. He cannot be in two states at once. Understanding how state works opens up understanding of quite a few biblical concepts.