If there is one thing that God would have His people do amid the rising apostasy of our day it is to show their colors. As the enemy comes in like a flood, even Bible-believing Christians are apt to hide a banner which they should unfurl and boldly display. That banner is Christ. How many believers fear to speak up for Him because His name is increasingly despised!
But, as in any war of any size, many and varied flags are carried into battle, this is so in the Christian conflict too, for the Bible, godly living, faithful comrades, etc., are all banners by which we should take our stand, flags we should display.
One such banner is fundamentalism, a slogan, a battle cry, which many believers are putting aside and hiding away just when they should display and wave it boldly. Some, recognizing the spiritual decline among fundamentalists, prefer to simply be called believers or Christians. We can appreciate this point of view but do not feel it is valid in this time of spiritual crisis.
At a time when the fundamentals of the Christian faith are being threatened as never before, we can do much to show that we stand for these basic doctrines, identifying ourselves openly with them by calling ourselves fundamentalists. The rapid pace at which the apostasy is rising about us makes it the more urgent that we display this banner. We believe that there is strong Scriptural support for this view, e.g., in Acts 23:6, where we read that Paul called himself a Pharisee to show that he stood for basic Bible doctrine and against those who denied it.
Bible-believing Christian: show your colors! source