In a conversation over lunch several years ago with a friend, who I knew did not profess Christian faith, he told me "I've made it just fine for 36 years without God, what do I need him for now?" Prompted, I believe, by the Holy Spirit, I responded: "how do you know?" "How do I know what?" he replied. "How do you know you've made it 36 years 'without God'?, I said, "how do you know he hasn't been involved in every area of your life since the day you were born?, I continued.

There was long pause. I said nothing. Finally he said slowly, "I never considered that before."

The following Sunday, my friend's wife, who was a Christian, came up to me at church and said "What did you say to my husband at lunch last Thursday? He's been moody ever since."

"Praise God", I said, "he's contemplating a question I asked him."

Not a month later, at another lunch, my friend admitted he had no answer for my question and that it had been nagging him. Not long after that, he admitted that it might be possible that God had indeed been present in his life, though he didn't know it and hadn't been aware of it. (Ah, prevenient grace!) Once he got to that point, the step to becomming a Christian was easy. It's been over 12 years, and my friend and dear brother-in-Christ has become one of the most thoughtful, dedicated, loving Christian man I know.
He's been actively involved in jr/sr high ministry for years as an adult volunteer and who knows how many of those young people have had their lives forever changed by the Gospel because of my friend's ministry in their lives.

And it all started with a question: "How do you know?"