The particle with which Paul begins this verse indicates that this is a continuation of the argument begun in the preceding verses. In some languages the most appropriate connective at this point would be an expression of cause—for example, “because the scripture says” or “the reason he cannot boast is that the scripture says.”

Scripture (the reference is to Genesis 15.6) supports Paul’s argument that God accepted Abraham as righteous only because Abraham believed God. Because of his faith God accepted him as righteous translates a passive construction in Greek (“it was counted to him for righteousness”). The agent indicated by the passive verb (“was counted”) is God, and the subject (“it”) is Abraham’s faith. Thus the construction means that God accepted Abraham as righteous because of his faith. The phrase because of his faith may frequently be recast as a verb expression—for example, “because he believed God” or “because he trusted God.” The term accepted may also be rendered as “regarded.” This provides a basis for direct contrast with not regarded in verse 4. In fact, in some languages this may be rendered rather idiomatically as “looked at him as one who is,” “counted him among those who are,” or “put the mark of righteous on him.”

Quoted with permission from Newman, Barclay M. and Nida, Eugene A. A Handbook on Paul’s Letter to the Romans. (UBS Handbook Series). New York: UBS, 1973. For this and other handbooks for translators see here .