Isaiah 55:1. Ho, everyone who thirsts, come to the waters; and he who has no money.
This is an exhortation for Christians in the midst of their trials, lest disgust take control of all of them. This is a most destructive pestilence in the church. We must be acutely on guard and alert, although we dwell in the sluggish flesh, and be militant in the exercise of the Word. No matter how much the secure flesh sleeps, as in the case of those who are seized by the pestilence, we must nevertheless persevere against this temptation and overcome it. Let no one seem to himself to have accomplished much in Scripture and to have heard many things, since in spite of that he loses the knowledge of the Word in forgetfulness day by day. From there let the mind be restored and recleansed as from a fog of ignorance, so that the heat and fervor in the Word may increase against the gates of death. Where people have been especially trained in the Word, there they are most negligent. This is a common complaint of preachers. Such exhortation is therefore especially necessary, lest they fall into contempt and loathing of the Word.
Everyone who thirsts, etc. The church is the assembly that clings to the Word, an assembly that is in need, in hunger and thirst. Therefore it attracts those who seek and love the Word and deals with them, lest they be slothful or give up. It is as if he were saying: “Embrace this holy teaching which is applied and offered to you free of charge.” Since it is a free gift, it is not to be acquired by one’s own payment, something that only the godly souls understand. The ungodly world wants to be deceived. It does not receive things offered free of charge but spurns them as worthless. Yet it embraces the precious papistic things and does so even at a high price. Formerly the pope gnawed so much wealth away from Germany, and yet the Germans most vehemently strove to obtain his wares. At length so much was expended and set forth for those magnificent cloisters, and they were therefore regarded with the highest reverence. All things that are free are accounted worthless. Thus the Gospel, offered to the world free of charge, is not accepted. Only the simple and unlettered pay attention to it, receive it, and embrace it zealously, something that we scarcely achieve by supreme vigils, frequent readings, and sermons” (Luther’s Works, v. 17, p. 249).