An excerpt from this short but powerful treatise from 1521:

“Be sure, moreover, that you do not make Christ into a Moses, as if Christ did nothing more than teach and provide examples as the other saints do, as if the gospel were simply a textbook of teachings or laws. Therefore you should grasp Christ, his words, works, and sufferings, in a twofold manner. First as an example that is presented to you, which you should follow and imitate. As St. Peter says in I Peter 4 [2:21], ‘Christ suffered for us, thereby leaving us an example.’ Thus when you see how he prays, fasts, helps people, and shows them love, so also you should do, both for yourself and for your neighbor. However this is the smallest part of the gospel, on the basis of which it cannot yet even be called gospel. For on this level Christ is of no more help to you than some other saint. His life remains his own and does not as yet contribute anything to you.

In short this mode [of understanding Christ] does not make Christians but only hypocrites. You must grasp Christ at a much higher level. Even though this higher level has for a long time been the very best, the preaching of it has been something rare. The chief article and foundation of the gospel is that before you take Christ as an example, you accept and recognize him as gift, as a present that God has given you and that is your own. This means that when you see or hear of Christ doing or suffering something, you do not doubt that Christ himself, with his deeds and suffering, belongs to you. On this you may depend as surely as if you had done it yourself; indeed as if you were Christ himself. See, this is what it means to have a proper grasp of the gospel, that is, of the overwhelming goodness of God, which which neither prophet, nor apostle, nor angel was ever able fully to express, and which no heart could adequately fathom or marvel at. This is the great fire of the love of God for us, whereby the heart and conscience become happy, secure, and content. This is what preaching the Christian faith means. This is why such preaching is called gospel, which in German means a joyful, good, and comforting ‘message'; and this is why the apostles are called the ‘twelve messengers.'”