Faith is not the abandonment of reason. People who think faith needs to be divorced from our intellectual faculties have in effect abandoned the very possibility of discernment.
The notion that logic and sound reason are hostile to faith actually substitutes irrationality for genuine faith. Irrationality and discernment are polar opposites.
When Paul prayed that the Philippians' love would "abound still more and more in real knowledge and all discernment" (Phil. 1:9), he was affirming the rationality of true faith. He also meant to suggest that knowledge and discernment necessarily go hand in hand with genuine spiritual growth.
Biblical faith, therefore, is rational. It is reasonable. It is intelligent. It makes good sense. And spiritual truth is meant to be rationally contemplated, examined logically, studied, analyzed, and employed as the only reliable basis for making wise judgments. That process is precisely what Scripture calls discernment.
The church today is sadly lacking in discernment, and all too apathetic about the problem. We need to remember that God's truth is a precious commodity that must be handled carefully--not diluted with whimsical beliefs or bound up in human traditions. When a church loses its will to discern between sound doctrine and error, between good and evil, between truth and lies, that church is doomed.
The apostle John drew a very sharp distinction between Christianity and the spirit of antichrist--and he zealously held the line: "Anyone who goes too far and does not abide in the teaching of Christ, does not have God; the one who abides in the teaching, he has both the Father and the Son. If anyone comes to you and does not bring this teaching, do not receive him into your house, and do not give him a greeting; for the one who gives him a greeting participates in his evil deeds" (2 Jn. 9-11). Thus he commanded those under his spiritual oversight to be watchful and discerning--and to have nothing to do with Christ-denying error or the purveyors of it.
Contrast today's Christians who soothe themselves with the opinion that few things are really black and white. Doctrinal issues, moral questions, and Christian principles are all cast in hues of gray. No one is supposed to draw any definitive lines or declare any absolutes. Every person is encouraged to do what is right in his own eyes--exactly what God forbade (cf. Deut. 12:8; Judg. 17:6; 21:25).
The church will never manifest its power in society until we regain a passionate love for truth and a corollary hatred for error. True Christians cannot condone or disregard anti-Christian influences in their midst and expect to enjoy God's blessing. "Now it is high time to awake out of sleep: for now is our salvation nearer than when we believed. The night is far spent, the day is at hand: let us therefore cast off the works of darkness, and let us put on the armour of light" (Rom. 13:11-12, KJV).