Excerpt from Evangelizing the Mind:

The gospel presupposes a worldview. The fact that this idea sounds unsettling to us shows how far we’ve come from the Bible’s teaching.  A worldview is a way of viewing the world.  It’s a set of assumptions that everybody has by which we interpret what goes on around us and inside us.  There is a Christian worldview and a Buddhist worldview and a Hindu worldview and a secular worldview and New Age worldview and Marxist worldview and variations and combinations of each.  Whatever we experience in this world, you and I interpret through the grid of our instinctive assumptions.  Those assumptions comprise our worldview.  Worldviews are like pancreases: everybody has one, even if we don’t know it or think about it.

The gospel assumes that we grasp certain truths, that we adopt a basic worldview.  We don’t preach the gospel in an intellectual vacuum.  The minute we say, “Jesus saves,” we must ask, “Who is Jesus? and “Saves us from what?” and then we must face the fact that the gospel presupposes a worldview.  This is easy to prove.

Suppose you’re conversing with an unbelieving colleague whose spiritual condition you’re desperately concerned about.  This is the first time you’ve ever really gotten into spiritual matters.  You don’t specifically know where he or she stands.  You start with, “I’m concerned with your eternal destiny.  How do you stand with God?”

Let’s suppose your colleague replies, “I don’t know much about God, but sure, I’d like to be right with God.”

And you respond, “Do you know that you — like all of us — were born into sin and our sin separates from God and that we stand under God’s judgment?”

And your colleague, good postmodern that he is, says, “I like God but I don’t like that idea of God.  God’s not judgmental.  He accepts everybody as they are.  Sure, we’ve all failed and done a few bad things, but the only ‘sins’ God cares about are racism and homophobia and multinational corporations and judgmentalism.  I believe in God, but I don’t believe I’m much of a sinner and, at any rate, I don’t think he’d judge me because I’m not perfect.”

You wouldn’t say (would you?), “That’s OK.  You can still trust Jesus.  He’ll take you just as you are.  You don’t need to admit you’re a sinner.  You don’t need to acknowledge that you deserve God’s judgment.  You don’t need to repent.  Just trust Jesus.”

No, you’d say, “You’re a sinner.  You can’t become a Christian until you admit you’ve sinned by breaking God’s law.  You must see that you’re accountable to God and deserve his judgment.  After all, that’s the reason Jesus had to die.  If people aren’t sinners, there was no reason for the Cross.”

If you’d respond to your colleague that way, you’re admitting that the gospel presupposes a worldview.  You’re saying (as you should) that certain beliefs are incompatible with the reception of the gospel.  The gospel saves from sin, and if we don’t repent of sin, we can’t be saved.

This is why at the very beginning of Jesus’ ministry John the Baptist laid the groundwork by preaching repentance (Mt. 3:1–2).  His listeners who refused to repent of their sins would face God’s righteous judgment (vv. 7–12). Jesus continued that message of repentance as part of his gospel preaching (Mt. 4:17).  This is why David Wells is correct to observe in The Courage to be Protestant that the gospel is understandable only in terms of a moral universe.  The gospel doesn’t harmonize with a conceptual universe in which man is his own god, in which truth is relative, in which guilt is merely subjective, in which there is no final judgment, in which all religions lead to the same place, and in which Jesus is one great religious figure among many.  The gospel is simply incompatible with these ideas.  This is another way of saying that the gospel demands that sinners give up certain false ideas before they can be saved.

So, when we preach the gospel to poor, hell-bound sinners, we’re preaching a gospel that demands they repent of their rebellious thinking, not just their rebellious emotions, their rebellious morals, their rebellious will, and their rebellious instincts.

The gospel presupposes a worldview.  This is why the Bible starts with Genesis 1:1 and not John 3:16.