Christianity entails an objective…

[Christianity] entails an objective reality outside myself that includes the reality of God’s existence and the truth revealed to us in His Word.

Ronald Nash, from Great Divides, p. 12

Philosophers who reject Christianity…

It is important to see that apologetics is not an activity reserved for philosophers who also happen to be religious believers. Much that passes as philosophy of religion is really apologetics as practiced by individuals who reject tenets of religious belief; I do not say this to be critical of philosophers of religion who may also happen to be atheists. My point is that philosophers who reject the Christian religion do not suddenly become, by virtue of this fact alone, more objective or rational or open-minded than philosophers who are Christians or Jews.

Ronald Nash, quoted in Love Your God With All Your Mind by J. P. Moreland, kindle location 1609