Jamieson, Fausset and Brown on Romans 8:10-11

10-11. And if Christ be in you--by His indwelling Spirit in virtue of which we have one life with him.

the body--"the body indeed."

is dead because of--"by reason of"

sin; but the spirit is life because--or, "by reason"

of righteousness--The word "indeed," which the original requires, is of the nature of a concession--"I grant you that the body is dead ... and so far redemption is incomplete, but," &c.; that is, "If Christ be in you by His indwelling Spirit, though your 'bodies' have to pass through the stage of 'death' in consequence of the first Adam's 'sin,' your spirit is instinct with new and undying 'life,' brought in by the 'righteousness' of the second Adam" [Tholuck, Meyer, and Alford in part, but only Hodge entirely].