In the Old Testament, righteousness came by people behaving. The law could witness to God’s righteousness, but it could not provide for it. It was a temporary solution for a permanent fix that only Jesus can provide. His blood could only bridge the gap for. Christ's birth, death, and resurrection mean that righteousness now comes through faith in Jesus Christ for all who believe.
Faith is only as good as its object. If my faith is on my effort than I am in trouble but if my faith is anchored to Jesus – He is never going to leave me or forsake me.