The sad reality is that Luther is often read by Lutherans through the lens of the modern day divisions of Rome and Wittenberg and with a view toward enhancing the divisions between us rather than a more objective read of Luther within the framework of his own words and time. In addition, we often blur the distinction between the words of Luther that inform and shape Lutherans (namely, the few words of Luther that form part of the Lutheran Confessions) and the rest of Luther which has no binding force upon Lutheran doctrine or confession. I am not suggesting that Luther is peripheral to the Lutherans but only reminding us that Luther's words (apart from the Catechisms and the Smalcald Articles) are important but not definitive. Only the Book of Concord is.
Secondly, Luther is cherry picked for statements often used outside the context of Luther's time or intent to address issues and conflicts in our own day. This is not necessarily wrong because Luther did speak to issues we face today but it is incumbent upon us to make sure that Luther's words are not torn out of context or some of Luther's words used to define all of what Luther said. Finally, the words of Luther we often resonate with are not necessarily the most popular expressions Luther himself used in his preaching and teaching. Again, this is not necessarily wrong but it does place the burden upon us to make sure we do not make more of some of these turns of a phrase than Luther himself did or we risk being unfaithful to him and to the Lutheran faith.
The young Luther or the old Luther, the catholic Luther or the protestant Luther, the firebrand Luther or the conciliatory Luther... Which Luther is the real Luther? Well, all of them. Luther cannot be cut up and subdivided in ways that betray him and his words. Luther with all his faults and with all his genius must be taken as a whole and not defined by one moment in time or one word spoken or written.
Pastor Jackson summarized his point with words I quote below but I would commend his whole article to you. Whether you are Roman, Reformed, Evangelical, or Lutheran, we need to make sure we do not paint a picture of Luther that he would reject. The temptation is great to abuse Luther but the value of keeping Luther straight is key not only to the future of Lutheranism but to the general ecumenical cause.
Catholics should resist importing from today's Lutherans a view of Luther that Luther himself would not have recognized. Instead, I suggest that Catholics—and Lutherans—consider a perspective on Luther promoted by many insightful Catholics. In Luther’s Faith, Catholic theologian Daniel Olivier portrayed Luther as one who was enamored of Christ, with a fierce love and loyalty that drove his theology. Pope Benedict XVI echoed this sentiment in a 2011 speech:
Luther’s thinking, his whole spirituality, was thoroughly Christocentric: “What promotes Christ’s cause” was for Luther the decisive hermeneutical criterion for the exegesis of sacred Scripture. This presupposes, however, that Christ is at the heart of our spirituality and that love for him, living in communion with him, is what guides our life.That perspective on Luther does not well serve the polemicist, whether Catholic or Lutheran. But, it is the truth, and it is just that Christocentric spirituality, that intense love of the Lord Jesus, that I believe should be considered a hallmark of Luther’s theology, over and against “the Simul.”