"Although They Knew God ... They Suppressed the Truth..."
The opportunities are wide open for Christians to speak with secular people these days, especially if you live in a metropolitan area. The average hipster you may meet in the medium to big sized city is a secularist who may listen to NPR, has a liberal, ecological, and/or anti-capitalist political ideology ... wears vintage clothing from a thrift store and consumes ethically. He or she often either rides a bike, uses public transportation or even may be driving a hybrid or bio-diesel vehicle. This person is deeply concerned with the ethical treatment of animals, is strongly against slavery, torture, racism and political oppression against women. In other words, he takes morality very seriously. Another characteristic of this individual is that he/she thinks Christianity is irrelevant at best.
Since we deeply care about the eternal destinies of such individuals how should we go about reaching such a person with the gospel? Where would you start?
Once of the more effective ways, I have found, is to remember that that your secular friend already knows God exists. He/she knows God exists and lives as if He does. In Romans chapter 1 Paul clearly teaches this about all people when he says, "For although they knew God" (verse 21) "...by their unrighteousness suppress the truth" (verse 18).
But how can we demonstrate to your friends that they already believe in God, when intellectually they deny His existence?
While there are many ways this could be done, I would like to suggest one way that I have found to be quite persuasive: The knowledge of God through their own morality.