Typology and Higher Form of Somatic Existence

Why does Paul, when asked about the nature of the resurrection body and after beginning to contrast the believer's dead body with his resurrection body, suddenly expand the comparison to include the creation body? Apparently his interest is to show that from the beginning, prior to the fall, a higher or different kind of body than the body of Adam, the psychical body, is in view. Adam, by virtue of creation (not because of sin), anticipates and points to another, higher form of somatic existence. The principle of typology enunciated in Romans 5:14 is present here, albeit somewhat differently: the creation body of Adam is "a type of the one to come." This suggestion of typology helps to illumine the use of Genesis 2:7 in 1 Cor 15:45, especially the addition in 1 Cor 15:45c