For any one can easily see that these two--the promise and faith--must go together. For without the promise there is nothing to believe, while without faith the promise, remains without effect; for it is established and fulfilled through faith. From this every one will readily gather that the mass, which is nothing else than the promise, is approached and observed only in this faith, without which whatever prayers, preparations, works, signs of the cross, or genuflections are brought to it, are incitements to impiety rather than exercises of piety; for they who come thus prepared are wont to imagine themselves on that account justly entitled to approach the altar, when in reality they are less prepared than at any other time and in any other work, by reason of the unbelief which they bring with them. How many priests will you find every day offering the sacrifice of the mass, who accuse themselves of a horrible crime if they--wretched men!--commit a trifling, blunder, such as putting on the wrong robe or forgetting to wash their hands or stumbling over their prayers; but that they neither regard nor believe the mass itself, namely, the divine promise--this causes them not the slightest qualms of conscience. O worthless religion of this our age, the most godless and thankless of all ages!
Hence the only worthy preparation and proper use of the mass is faith in the mass, that is to say, in the divine promise. Whoever, therefore, is minded to approach the altar and to receive the sacrament, let him beware of appearing empty before the Lord God [Ex. 23:15; 34:20]. But he will appear empty unless he has faith in the mass, or this new testament. What godless work that he could commit would be a more grievous crime against the truth of God, than this unbelief of his, by which, as much as in him lies, he convicts God of being a liar and a maker of empty promises? The safest course, therefore, will be to go to mass in the same spirit in which you would go to hear any other promise of God; that is, not to be ready to perform and bring many works, but to believe and receive all that is there promised, or proclaimed by the priest as having been promised to you. If you do not go in this spirit, beware of going at all; you will surely go to your condemnation.