Those are two great temptations that hinder us inwardly in our prayer, and outwardly try to chase us away from it. Therefore all we can do is to go on crying to God, asking Him to strengthen and advance His Word in us and to restrain the persecutors and the sects so that it is not extinguished. Now, the third enemy is the strongest of all, the devil himself. He has us at a great disadvantage for two reasons: by nature we are not good; and in addition we are weak in faith and in spirit. Thus he invades my own castle and baffles against me. He also has the world on his side, and he incites all the sects against me. Through them he shoots his flaming, poisonous darts (Eph. 6:16) at me, to wear me down, to extinguish the Word in me again and to smother it, and to establish his control as he once had it, without any danger of being expelled. There, you see, are three troubles that press us down hard and will not get off our neck as long as we have life and breath. Hence we have continual reason for prayer and invocation. This is why He adds the words “ask,” “seek,” and “knock,” to indicate that we do not have everything yet but that our situation is one of shortcomings and needs everywhere. If we had everything, we would not need to ask or seek; if we were already in heaven, we would not need to knock. (Luther’s Works, v. 21, pages 230-231).
