Then they began to say: 'Yes, but how can we know what is God's Word, and what is right or wrong? We must learn this from the Pope and the councils.' Very well then, let them conclude and say what they please, yet I will reply, you cannot put your confidence in that nor thus satisfy your conscience, for you must determine this matter yourself, for your very life depends upon it. Therefore God must speak to your heart: This is God's Word; otherwise you are undecided.
Martin LutherWhilst a man is persuaded that he has it in his power to contribute anything, be it ever so little, to his salvation, he remains in carnal self-confidence; he is not a self-despairer, and therefore is not duly humbled before God, he believes he may lend a helping hand in his salvation, but on the contrary, whoever is truly convinced that the whole work depends singly on the will of God, such a person renounces his own will and strength; he waits and prays for the operation of God, nor waits and prays in vain
Martin LutherIn Romans 7, St. Paul says, "The law is spiritual." What does that mean? If the law were physical, then it could be satisfied by works, but since it is spiritual, no one can satisfy it unless everything he does springs from the depths of the heart. But no one can give such a heart except the Spirit of God, who makes the person be like the law, so that he actually conceives a heartfelt longing for the law and henceforward does everything, not through fear or coercion, but from a free heart.
Martin Luther