Therefore every Christian should pay attention to this admonition. It is, in the first place, a commandment, as much as the previous statement, “Judge not” is a commandment. He should know that he is obliged to practice this Christian work. He should not be like that peasant who said: “I give grain to my minister, and he prays for me”; or like the people who think: “What is the use of my praying? If I do not pray, others do.” We must not suppose that it is no concern of ours or that it is left up to our free choice; but I have given more detailed admonition on this elsewhere.¹⁵ In the second place, you have here the comforting promise and rich assurance that He attaches to prayer, to make it evident that He cares about it and to teach us to think about prayer as something dear and precious before God, because His admonition is so serious and His invitation so friendly, and He promises that we shall not ask in vain. Even if we had no other reason or attraction than this rich and friendly word, it should be enough to prompt us to pray. I shall not even talk about how dear His exhortation is or how sublime His command or how desperate our need. (Luther’s Works, v. 21, pages 229-230).

Now, what He intends to say is this: “I have given you instructions about how you ought to live and what you ought to watch out for. In addition, it is necessary that you ask and that you have the confidence to go right on seeking and knocking without becoming lazy or lax in it. You will have need of asking, seeking, and knocking. Though doctrine and life may both have begun all right, we shall have to suffer from all sorts of transgressions and offenses that hinder us daily and keep us from progressing. We battle against these continually with all our might, but the strongest shield we have is prayer. If we do not use that, it is impossible for us to hold our own and to go on being Christians. We can plainly see now not only the sort of obstacles that oppose the Gospel every day, but also our own neglect of prayer and our attitude, as though this warning and admonition did not refer to us and we did not need prayer any more, now that the useless chattering and muttering of the rosaries and the other idolatrous prayers have stopped. All this is not a good sign, and it makes me afraid that some great misfortune which we could have prevented will overtake us. (Luther’s Works, v. 21, pages 229).