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 LutherIt is as if a wolf devoured a sheep and the sheep were so powerful that it transformed the wolf and turned him into a sheep. So, when we eat Christ's flesh physically and spiritually, the food is so powerful that it transforms us.
Martin LutherAn angel is a spiritual creature created by God without a body, for the service of Christendom and of the church.
Martin LutherThe Holy Spirit is no Skeptic, & the things He has written in our hearts are not doubts or opinions, but assertions - surer & more certain than sense & life itself.
Martin Luther[Christ's] mission and work it is to help against sin and death, to justify and bring life. He has placed his help in baptism and the Sacrament [i.e., communion/Eucharist/Lord's supper], and incorporated it in the Word and preaching. To our eyes Baptism [capitalized in original] appears to be nothing more than ordinary water, and the Sacrament of Christ's body and blood simple bread and wine, like other bread and wine, and the sermon, hot air from a man's mouth. But we must not trust what our eyes see.
Martin LutherWhere faith is not continually kept in motion and exercised, it weakens and decreases, so that it must indeed vanish; and yet we do not see nor feel this weakness ourselves, except in times of need and temptation, when unbelief rages too strongly; and yet for that very reason faith must have temptations in which it may battle and grow.
Martin Luther