I had one of my top 10 pastoral conversations today with a couple fairly new to Christ who are absolutely DEVOURING the Bible. Nice. Love it.
And they ask questions.
A lot of their influences have been from the Reformed (Calvinist) tradition. Luther and Calvin were both reformers of the early 16th century. They disagreed heartily.
Yet today Biblical Lutherans have found friendship in Calvinist circles. One reason is that it is increasingly hard to find denominations that hold to the Bible as 100% God's Word and therefore see mankind as basically evil and in need of redemption (as opposed to basically good and in need of education and opportunity). Another is that there really is substantial agreement on some of the major points of Calvinism.
But not entirely. The main difference is the place of reason in the theological system. As I told a Calvinist friend yesterday, "My guy left a lot to the mystery of God. Your guy rarely said 'I don't know.'" Indeed, where God didn't speak Luther tended to remain silent- even if it was awkward or seemed inconsistent with human reason. Calvin filled in the blanks.
One example is election. Luther said that before time began God chose people to be saved (Ephesians1 and Romans 11 both will help here). Calvin said, given this, that before time began God also chose people to be damned by not choosing them to be saved. I can't list Scripture for this because it doesn't exist. It is a reason-built extrapolation. And there are other examples.
I saw this video recently. The guy is a bit snarky, but I think you'll benefit from it.