Lutherans are Christians (See our "What We Believe" page). We follow the teaching of Sola Scriptura (Scripture alone) rediscovered Martin Luther. Therefore, to be a Lutheran means, simply, to believe that Holy Scripture is sufficient for everything we need to know about The Trinity, Salvation, Prayer, His Will, etc.
Many people get Martin Luther (the German Reformer) confused with Martin Luther King Jr. (the Civil Rights Activist). The Lutherans derive their name from Martin Luther, the German Monk who reformed the church. The Lutherans are the first, and oldest Protestants. This all started on October 31, 1517, when Luther, a Catholic monk, posted his 95 Theses as a challenge to the doctrine and practice of the Roman Catholic Church, hoping to reform the teachings that were inconsistent with Holy Scripture (e.g., Justification, Indulgences, Invocation of the Saints, the Papacy, the Sacrifice of the Mass, etc.). For Luther, tradition and reason do not rule or inform Scripture, but Holy Scripture rules and forms our reason and tradition! Martin Luther was not looking to start his own "denomination," yet, the Roman Catholic Church declared him a heretic for his teaching that Holy Scripture is the only source and norm for theology.
Those who followed the teaching of Sola Scriptura from Martin Luther were labeled "Lutherans." This is a name that Luther himself hated, yet, the name stuck. So, to this day, those who believe that Scripture is the primary authority for faith and life and that we are saved by grace through faith in Christ alone (Ephesians 2:8), are called Lutherans. Every church has a statement of what they believe. For us, what we believe, teach, and confess is all written down and collected into the Book of Concord, that is, the Lutheran Confessions. This is what our church, The Lutheran Church—Missouri Synod (LCMS), officially teaches, confesses to all. Therefore, to determine if someone is actually a Lutheran, you must see how faithful they are to Holy Scripture and see if they teach exactly what is in it. If you are interested in what the Lutherans teach, please speak to Pastor Rojas!