I am not quite satisfied with 'as;' but it is the nearest approach to the sense in English. 'For,' I object to; because then faith is made of positive worth, having the value of righteousness; whereas the sense is that he was holden for righteous in virtue of faith. 'For' does not go far enough as righteousness; too far as to a positive value of faith. Faith might be reckoned for righteousness, and yet the righteousness come short of what was required; whereas if it be reckoned as righteousness, then the full value of righteousness, as such, is seen: 'the man was held to have righteousness.' It is a Hebrew form. See Ps. 106.31. Gen. 15.6, where there is no preposition, makes the force of the expression plain.