'Merely' in the Bible

For it is not merely those who hear the Law who are righteous in God's sight. No, it is those who follow the Law, who will be justified.

Or is God the God of Jews only? Is He not also the God of Gentiles [who were not given the Law]? Yes, of Gentiles also,

and [that he would be] the [spiritual] father of those circumcised who are not only circumcised, but who also walk in the steps of the faith of our father Abraham which he had before he was circumcised.

so that the promise should be made sure to all Abraham's true descendants; not merely to those who are righteous through the Law, but to those who are righteous through a faith like that of Abraham. Thus in the sight of God in whom he believed, who gives life to the dead and makes reference to things that do not exist, as though they did, Abraham is the forefather of all of us. As it is written, "I have appointed you to be the forefather of many nations."

For we know that the Law is spiritual, but I am merely human, sold as a slave to sin.

That is, it is not merely the children born through natural descent who were regarded as God's children, but it is the children born through the promise who were regarded as descendants.