Nebraskan Ben Sasse, 44, is a husband, father, and graduate of both Harvard and Yale who won election to the U.S. Senate in 2014. Last year he gave a much-discussed maiden floor speech on why “the people despise us.” This year he drew national attention—and some calls to run for president—when he openly opposed Republican presidential nominee Donald Trump. I recently sat down with Sasse in his Capitol Hill office to discuss his theological formation and how it influences his political philosophy.

How did you come to faith in Christ? I am blessed to have grown up in a church where the gospel had long been faithfully preached. I knew myself to be a sinner and Christ as my only hope for as long as I can recall. In the Lutheran tradition you’re called to remember your baptism and what it means, so I self-consciously affirmed the faith in my confirmation class in April-May 1986. I was confirmed and became a communicant member at age 14.

Are you denominationally a Lutheran now? I am a “Lutero-Calvinist.” I was raised Missouri Synod Lutheran. I am in love with the Lutheran tradition, but I am a member of a PCA church—Grace Church in Fremont, Neb.

How did you become theologically Reformed? In college I was very involved in evangelical and parachurch groups—Fellowship of Christian Athletes, Campus Crusade (my wife is a former Cru staffer). Although I grew up in the Lutheran tradition and was very involved in FCA in high school, I didn’t have a lot of clarity about the differentiation of theological views inside Protestantism. In college I became a part of evangelistic groups that were very action-oriented and not always very theologically reflective. There were things that I couldn’t make sense of about the connection between faith and practice. So I started reading theology on purpose to make sense of things I was wrestling with and to try to understand the text better. I started reading a lot of Luther and read some B.B. Warfield. Bob Godfrey (president of Westminster Seminary California), Mike Horton (White Horse Inn media and Modern Reformation magazine), and R.C. Sproul were all really influential in my college clarification of being Calvinistic, Reformed.

‘I get the chance to live out a life of gratitude to God by trying to serve my neighbor, and politics is one of many secular callings—like building good shoes or speedboats.’

You realized you were Reformed, or that reading changed your mind? It changed my mind. Sproul’s Chosen by God and The Holiness of God were really, really significant. Isaiah 6 is a lead-in passage of The Holiness of God. It scared the heck out of me.

And eventually you became the president of a Lutheran college. I was president of Midland University, a Lutheran college. I wrote my undergraduate thesis on Luther and the just war tradition. My master’s thesis is on Calvin and the third use of the law. The most important use of the law is the condemnatory use that drives us to Christ. This is the “first use”—the way the law condemns us, driving us to conversion. The “second use” is the ceremonial or civil use for Old Testament Israel. The “third use” is how the law is used in sanctification—as a guide to righteousness.

How many of your Senate colleagues are Bible-believing Christians? I have no idea. I have spent a lot of time interviewing people here about policy challenges, the institutional and cultural history of the Senate, but I’ve only had meaningful theological discussions with a dozen people, so I don’t have enough information to judge.

Is James Lankford one of the senators for meaningful theological discussion? James and I have talked theology a lot. Tim Scott, Steve Daines—we all can talk theology.

How does your faith and theology inform policy fights and discussions? Three thoughts: First, a basic Christian orientation to living in the world. We live in the already and the not-yet, so as a Christian I am convicted of my sin and aware of Jesus’ salvific work both by imputation and by atonement on my behalf. Now I get the chance to live out a life of gratitude to God by trying to serve my neighbor, and politics is one of many secular callings—like building good shoes or speedboats.

Second? The American system is a glorious inheritance, because it is an anti-statist tradition. The purpose of American limited government is to make a broader, affirmational claim about human dignity and natural rights. Government doesn’t give us rights. We get rights from God via nature, and government is our shared project to secure those rights. The American system is a wonderful place for Christians to labor. We don’t have the challenges that Daniel had. We’re not being asked to bend the knee and worship Caesar. That is a glorious thing that we get to live in a state that doesn’t try and require idolatry. We should understand, affirm, and pass along that free tradition.

And third. People of goodwill are going to argue about policy. That is a good and healthy thing. We, as Christians, have a responsibility to do it in a way that doesn’t violate the Ninth Commandment. We don’t want to bear false witness against our neighbor, so we should assume our neighbor means well and try to characterize their position accurately, not beat a straw man. As it turns out, really believing in the dignity of your neighbor and loving your neighbor means that you want to try to refine and shape their best argument. Sometimes I’m going to be converted. There’s going to be a policy issue where I thought I knew the answer and somebody else has a better argument. I should be humble enough to actually be persuadable. If I’m going to try to persuade them, I want to do it by not misrepresenting their view. Some debates are genuine, where you’re actually open to wrestle with another idea. Other debates are faux, where all you’re really trying to do is beat someone. It turns out the latter is not only unpersuasive and ineffective—it’s really boring. It’s also dishonest.

What’s an example of an issue on which your mind has changed? Before I started paying close attention to foreign policy, I believed the popular myth that somehow we spend an insane amount on foreign aid. If you ask Americans how much money we’re spending on foreign aid, the most common guesstimate is 25 to 30 percent of the budget. It’s actually 24/100ths of 1 percent of the budget. Some of it is ineffectively spent. There is some fraud, waste, and abuse. And yet, done right, foreign aid, soft power, and the investment in the rule of law is a very important and effective lever to the U.S.’s own national security interests—what’s called global security interests.