"Say ye not, A confederacy, to all them to whom this people shall say, A confederacy; neither fear ye their fear, nor be afraid. Sanctify the LORD of hosts himself; and let him be your fear, and let him be your dread." (Isaiah 8:12-13)
The people of Judah were terrified by the imminent prospect of invasion by the cruel Assyrian hordes who had been further strengthened by a confederacy with Judah's own brethren in the ten-tribe kingdom of Israel. It is indeed cause for concern when compromising Christians join ranks with ungodly pagans in opposing those who defend the true word of God, for such a combination seems almost too strong to resist. A modern example is the current collaboration between the secular evolutionists and those Christian evolutionists and "progressive creationists" who oppose Christians who stand for the literal truth of the biblical record of creation and earth history.
This is cause only for concern, however, not for fear! Just as in Isaiah's day, we must fear God--not men. In the coming judgment it will be far easier to explain to God why we had too much faith in His word than too little!
These verses are referred to by the apostle Peter in a well-known New Testament passage: "Be not afraid of their terror, neither be troubled; But sanctify the Lord God in your hearts: and be ready always to give an answer to every man that asketh you a reason of the hope that is in you with meekness and fear" (1 Peter 3:14-15).
Therefore, when unbelievers and compromising believers join forces against those who fully believe the Bible, the proper response is not panic, or submission, or even belligerent opposition, but an implicit confidence in God and His word, accompanied by a gracious "answer" (literally "apologetic") in defense of the truth, given in a meek spirit and in fear only of God. HMM