I believe that many times, we as Christians do not engage in the battle for ideas because we are simply afraid. We are afraid an objection will come up that we can't answer. We are afraid we will be made to look foolish. Or perhaps we are afraid that a challenge will be presented that calls into question what we believe and everything that we hold dear.
The following quote from Christian author J.I. Packer exposes the fallacy of this type of thinking:
“The Evangelical is not afraid of facts, for he knows that all facts are God's facts; nor is he afraid of thinking, for he knows that all truth is God's truth, and right reason cannot endanger sound faith. He is called to love God with all his mind; and part of what this means is that, when confronted by those who, on professedly rational grounds, take exception to historic Christianity, he must set himself not merely to deplore or denounce them, but to out-think them. It is not his business to argue men into faith, for that cannot be done; but it is his business to demonstrate the intellectual adequacy of the biblical faith and the comparative inadequacy of its rivals, and to show the invalidity of the criticisms that are brought against it. This he seeks to do, not from any motive of intellectual self-justification, but for the glory of God and of His gospel. A confident intellectualism expressive of robust faith in God, whose Word is truth, is part of the historic evangelical tradition. If present-day Evangelicals fall short of this, they are false to their own principles and heritage.”
As the Bible says, "For God hath not given us the spirit of fear; but of power, and of love, and of a sound mind" (2 Tim. 1:7, KJV, Emphasis mine).
Courage and Godspeed,
Chad A. Gross
1) J.I. Packer, quoted in Fundamentalism and the Word of God.