Romans 4:2-5 is one of those passages, along with James 2:21-24, and Hebrews 11:8-10, which points to Abraham's faith and works through listening to God and forsaking all. The do-nothing preachers on both sides of the holiness debate rarely use these verses because they hate the forsake all teaching more than anything else Jesus taught. Instead they focus on the dead works of religion; rules about not swearing, paying your tithes, getting water baptised, etc.
But like Jesus said in the Beattitudes: Abraham hungered and thirsted after righteousness and it was his faith, exemplified by his good works—his willingness to give up everything including his own son, Isaac—was what justified Abraham before God. This is exactly what is missing in the church world today.