Imagine you spent countless hours studying scientific and philosophical objections to Christianity. You enrolled in the classes so you could defend the faith. You read the books. You practiced the arguments.

And you found out that no one really cared.

That’s the post-Christian world described by Sam Chan in his new book, How to Talk About Jesus (Without Being That Guy): Personal Evangelism in a Skeptical World (Zondervan). Chan is a public speaker for City Bible Forum in Australia and the award-winning author of Evangelism in a Skeptical World.

Chan told me that the old order of evangelism has been reversed. In a Billy Graham crusade or presentation of the Four Spiritual Laws, you heard the truth, you believed it, and then you lived it. Today, not so much, Chan says:

I argue even though ontologically and logically, that should be and ought to be the sequence, in practice, because we’re so post-Christian and people aren’t coming on a church bus anymore, it seems to be people journey into the faith by discovering, “Hey, this is livable. . . . So maybe it’s believable. Hey, if I can believe it, then it also must be true.”

This view informs what Chan identifies as the most powerful factor in determining belief and the secret sauce of evangelism, as he explained to me in this week’s episode of Gospelbound.