For - a mere particle of transition here [Tholuck], like “but” or “now.”
to be carnally minded - literally, “the mind” or “minding of the flesh” (Margin); that is, the pursuit of fleshly ends.
is death - not only “ends in” [Alford, etc.], but even now “is”; carrying death into its bosom, so that such are “dead while they live” (1Ti 5:6; Eph 2:1, Eph 2:5) [Philippi].
but to be spiritually minded - “the mind” or “minding of the spirit”; that is, the pursuit of spiritual objects.
is life and peace - not “life” only, in contrast with the “death” that is in the other pursuit, but “peace”; it is the very element of the soul’s deepest repose and true bliss.