What Do You Know for SURE?

I was in a manufacturing plant with a customer last week. Ear plugs in, safety glasses on, lots of noise. I was following him to a place where he was going to show me an unusual piece of machinery. As we were walking he turned back to me, grinned and said, "What do you know for sure?"
He may have meant to render me speechless, (which isn't too hard to do), and that's what happened. It really wasn't a good time to try to talk but I tried to recover quickly and said, "I know a few things for sure", but don't know if he heard me or not.
That's a good checking question to ask someone when you want to take their mind toward the reality of eternity and spiritual matters. The world, the flesh and Satan use uncertainty as the foundation of their assault on man; to block us from coming to that sure Rock of Salvation.
One of the very big differences between those who are God's sons by faith in Christ Jesus and those who are lost is the SURE knowledge of the most important matters of life. We are in His hands, nothing can separate us from Him. When/if we die, we know where we are going - for SURE. His work of redeeming us to a holy God by His blood is complete, sure and thankfully has no dependence on our merits or efforts.
Thank God, I know a few things for sure!