The idea of repentance has a distinctly intellectual side to it. Of course, that does not make it coldly intellectualistic; repentance has much more to it than simply a change of mind. But its focus is on the mind. Repentance means, at least, that our mind-set must change with respect to a certain lifestyle or way of thinking. Repentance, as we will see, must be part of our apologetic appeal. We dare not simply think that our responsibility in apologetics is to show that some deity might exist somewhere. Our responsibility is to tell the truth, the truth about Christianity, including the truth that God now "commands all people everywhere to repent" (Acts 17:30). We seek and desire, in defending the faith, to see a change of mind in those to whom we speak.
(Oliphint, K. Scott. The Battle Belongs to the Lord: The Power of Scripture for Defending Our Faith. Phillipsburg, NJ: P&R, 2003. Print. 5)