"Depart from evil, and do good; seek peace, and pursue it." -Psalm 34:14, KJV

God here gives us the way to succeed as righteous people: stop doing bad things, do good things, look for and make peace with others. It seems simplistic, but God gave these instructions even before Christ died. All we have to do to be righteous is, well, be righteous. We can never become perfect on this earth, but we can continue to improve with God's grace.