Albert Barnes on Ephesians 3:12

We have boldness. The word here used--παρρησιαν--means, properly, boldness of speaking, 2Cor 7:4, Jn 7:26, Acts 4:13,29,31. Here it seems to mean, "freedom of utterance;" and the idea is, that we may come to God now in prayer with confidence through the Lord Jesus. See Heb 4:16.

And access. Eph 2:18.

By the faith of him. By faith in him. The sense is, that we may now come confidently and boldly to the throne of grace for mercy in the name of the Redeemer. Boldness is not rashness, and faith is not presumption; but we may come without hesitating, and with an assurance that our prayers will be heard.

(d) "boldness" Heb 4:16 (*) "boldness" "freedom of speech"