See on Joh 1:4. The life which God bestows; life in Christ. See 1Jo 5:11.
Through the ignorance
The cause of the alienation. Not to be construed with darkened, since ignorance is the effect, and not the cause, of the darkness of the understanding.
Which is in them (τὴν οὖσαν ἐν αὐτοῖς)
The participle of the substantive verb expresses the deep-seated, indwelling character of the ignorance.
Hardening (πώρωσιν)
See on Mar 3:5. Dependent, like ignorance, on alienated. Arrange the whole clause thus: