John Murray: Faith is the means by which we take hold upon God's justifying righteousness

John Murray explains that faith brings us into possession of the righteousness required for justification, but faith itself is not the righteousness:

... the righteousness contemplated in justification is not faith itself but something that comes into our possession by faith ... [it is] righteousness by faith in contrast with righteousness by works ... [it is] a God-righteousness and it is a faith-righteousness ... [it is] brought to bear upon us by faith. (John Murray, The Epistle to the Romans, Appendix A: Justification)