John Murray on Romans 1:17 - "It is a God-righteousness."

Romans 1:17 - For in it [the gospel] the righteousness of God is revealed from faith for faith...

"It is a 'God-righteousness.' Because it is such, God is its author; it is a righteousness that meets all the demands of His justice and therfore avails before God. But the particular emphasis rests upon its divine property and is therefore contrasted not only with human unrighteousness but with human righteousness. Man-righteousness, even though [or, even if it were...] perfect and measuring up to all the demands of God's perfection, would never be adequate to the situation created by our sins. This is the glory of the gospel; as it is God's power operative unto salvation [verse 16] so is it God's righteousness superveing upon our sin and ruin. And it is God's power operative unto salvation because the righteousness of God is dynamically made manifest unto our justification. Nothing serves to point up the effectiveness, completeness, and irrevocableness of the justification which it is the apostle's purpose to establish and vindicate than this datum set forth at the outset--the righteousness which is unto justification is one characterized by the perfection belonging to all that God is and does. It is a 'God-righteousness.'"

-John Murray, The Epistle to the Romans, p. 31