Romans 4:12

Father of circumcision. That is, father of the circumcised. This is to be connected with “that he might be” (v. 11). It was God’s design that Abraham should pass on the rite of circumcision to all his physical descendants to be a sign of the faith they should share with him. Paul did not minimize the significance of circumcision, rightly understood (see ch. 3:1, 2). It was a privilege to be a member of the chosen race and to bear the seal of righteousness by faith.

Circumcision only. While Abraham was the physical ancestor of all circumcised Jews, he was the father, in the sense in which the term is used in this context, only of those who received circumcision in the same spirit and faith as he had. Mere circumcision was of no avail, but circumcision connected with a faith like Abraham’s marked those who were tally his descendants (chs. 2:28, 29; 9:6, 7).

Walk. Gr. stoicheo, “to follow a person [or thing],” “to be in line with,” “to agree with,” “to submit to.” As a military term it means “to move in line.” Compare the use of stoicheo in Gal. 5:25; Phil. 3:16. Abraham is the father of those who are not only circumcised but also “walk in the steps” and follow the example of the faith that he had before he was circumcised. The example of Abraham’s faith sheds further light on the meaning of genuine faith. His faith was not a momentary experience but the habit of a lifetime, revealing itself in consistent obedience and good works. God Himself testified that “Abraham obeyed my voice, and kept my charge, my commandments, my statutes, and my laws” (Gen. 26:5).