Was not our ancestor Abraham considered righteous for what he did when he offered his son Isaac on the altar? You see that his faith and his actions were working together, and his faith was made complete by what he did. And the scripture was fulfilled that says, "Abraham believed God, and it was credited to him as righteousness," and he was called God's friend.
Here is the evidence. We all know that Abraham was a man of faith, but I have come to believe that one of the key factors in whether or not a person's faith is genuine, is when they come to that point of decision and they choose God's way.
Choosing God's way is always a step of faith. God's way doesn't always seem the best from our viewpoint. Sometimes God's way seems to be the most difficult way. So faith is what bridges that gap and then we act in obedience. This is how our actions are the evidence of faith.
When a person chooses to deny self and follow Christ, they have evidenced true faith. When a person comes to that point of decision and simply states, "I know what God would have me to do, but I just don't want to do it" and then they don't do it... their lack of true faith is evident.