Here is the test between earnestness and insincerity. You say you wish to be a different man; Christ takes you at your word, so to speak; He offers to make you different. He says, "I will take away from you the heart of stone, the love of this world and its pleasures, if you will submit to My discipline." Here a man draws back. No; he cannot bear to lose the love of the world, to part with his present desires and tastes; he cannot consent to be changed. After all he is well satisfied at the bottom of his heart to remain as he is, only he wants his conscience taken out of the way. Did Christ offer to do this for him, if He would but make bitter sweet and sweet bitter, darkness light and light darkness, then he would hail the glad tidings of peace;—till then he needs Him not.
--Blessed John Henry Newman, Parochial and Plain Sermons, Volume 1, “Knowledge of God's Will without Obedience”