Purity of heart and life is something that every Christian should strive for.
Are you taking a good deep look into your soul and seeing that you are not as pure in heart as you thought? Do you see a little gray or black around the edges of your life. Maybe you find the blackness is deep within your heart. Hopelessness falls upon you. Despair not Jesus has brought help to us.
His words which we find in the bible have come our way in which if we give our obedience to will take all that dross and darkness out of our lives. When in faith we place our faith in Him and His word Jesus is able to carry us from a dirty white life to a pure white life.