Theology is what I sometimes call an "armchair sport". It's a academic debate between gentlemen, engaged in while smoking cigars, sitting in high-backed chairs and surrounded by old books. For me, the thinking and the debate itself is the sport. Theology exercises and disciplines the intellect, with the intended goal of "taking every thought captive to obey Christ" (2 Corinthians 10:5).
Me? I'm a big proponent of predestination myself. And I don't advocate for just any old predestination. I'll argue for super-secret double-probation superlapsarian predestination. God's active predestination of our lives is why I am able to "give thanks in all things" (1 Thess 5:18), because "for those who love God all things work together for good" (Rom 8:28).
The problem, as our free-will and Arminian friends will rightly point out, is that right theology not worked through can sometimes lead to wrong behavior. The topic of predestination is about what God does "behind the curtain". The topic IMO does not, and should not bleed over into an excuse for Christians to evangelize less (or not at all) contrary to what our Lord has already commanded in scripture.
I'm glad to discuss predestination with anyone willing to don the requisite smoking jacket, to pour their favorite libation, and to join me in the library to engage in the manly sport of theology. IMO theology is important. And when we leave that room and go out into the world, we should leave the debating back in the library, and (I hope) our common obedience to God, and affection for each other, should look the same to a watching world.
“Theology is the queen of the sciences and all other disciplines are her handmaidens.”
― R. C. Sproul“He that has doctrinal knowledge and speculation only, without affection, never is engaged in the business of religion.”
― Jonathan Edwards