Holding back on A W Tozer's analysis a little longer, let's look at where Christian fundamentalism has reached today.
In his book What People Ask About the Church, Dale Robbins writes: "In the broad sense, fundamentalism may be used to describe Christians who are uncompromising, conservative and who take their beliefs to the maximum - exactly how every believer should live." In all probability, this is how serious evangelical Christians the world over would describe themselves. It is therefore a neutral, general description, which distinguishes such believers from liberals on the one hand and ritualists on the other.
However, as Robbins points out: "In recent times, because of increased activism by those identified as fundamentalists, who have promoted unethical actions such as bringing violence against abortion clinics, some academic circles believe that fundamentalism has been redefined by our society... [In their eyes] fundamentalism has evolved into a legitimate form of extremism, with views too radical for the balanced, evangelical Christian."
The analogy with Islamic fundamentalists is never far away. That term only gained currency during the Iran Hostage Crisis of 1979-80. The media, in an attempt to explain the ideology of the Ayatollah to a Western audience, described it as "a fundamentalist version of Islam". So Islamic fundamentalism was a merging of religious teaching and social revolution, and this idea has now been carried back to Christianity - at least in the eyes of an onlooking world.
Now, therefore, some Christian theologians refer pejoratively as "fundamentalist" to any Christian thinking or plan of action which they see as too literal-minded and with the potential to rock the boat. On wonders what would they have said of Jesus Christ and the twelve Apostles? The persistent criticisms which they (and non-Christians) level at fundamentalist evangelicals are triumphalism (they make simplistic claims which they cannot prove) and selectivity (they are happy to be literal-minded about Jesus' miracles, but not about Christians sharing all things in common).
The key issue, as I would see it, is open-mindedness. Barry Morgan, Archbishop of Wales, puts it helpfully: The new fundamentalism of our age leads to the language of expulsion and exclusivity, of extremism and polarisation, and to the claim that, because God is on our side, he is not on yours. If we, as Christians, reach the point where we are no longer able to question, to "test all things and hold fast to that which is good" (1 Thessalonians 5:21), then our particular brand of fundamentalism is teetering on the edge of the very idealistic extremism we might condemn in others. A sorry state indeed!
