Fundamentalism is new to Christianity, and the result of a separation from the mystical, spiritual, and historical Church.
I am reminded of a title of a C.S. Lewis book: Your God is Too Small.
Legalism makes enemies of all who are unlike yourself, and that cannot be reconciled with a Gospel of "Good News" or what God has revealed of Himself in the New Covenant-- much less what He accomplished on the Cross.
The Bible is not a weapon, and if you insist on using it as such, there ought to be a "Conceal and Carry" law regulating who is authorized to use it.
You protest against gays at the grave side services of veterans and before their bereaved families and friends. You seek to LEGISLATE your faith so as to FORCE others to accept it.
Yet, the human soul is attracted to God by its own nature. While sin separates us, as does death, God the Son has provided a means to overcome all which separates us from Him.
The journey of such a soul, however, finds it very difficult to find that journey toward God inside a Church whose members and leaders would seek to block them from entrance-- intent on denying them access to grace. That is the failure of Fundamentalism.
To such, knowing Church history, the development of Christian theology, the great and early saints and theologians who fought against heresy, endured persecution, and passed on the teachings of the Apostles-- some before the Christian Bible even existed-- is a dangerous thing to be avoided.
But study these things, some of us do-- most of the Church does. The vast majority of the Church is engaged in theological dialogue with one another. The Fundamentalists except themselves-- deny themselves a place at the table by their refusal to read and study what the Church has always said about the faith.
So "God became man so that man[kind] might become God" is an alien expression to the Fundamentalist? I have yet to find one who even knows this, THE fundamental statement encompassing the Gospel and the Christian faith.
So are the Three Creeds (Apostles', Nicene, and Athanasian) and the Definition of Chalcedon-- all historic attempts by the educated leaders in attempt to preserve the authentic faith from before there was a canon of Christian scripture.
Such scholarship was used by the ancient Church to determine which, of many, sacred writings were authentic-- either written by Apostles, or by those who studied under one of the Apostles. Prior to that, the traditions had been passed down from bishop to bishop-- each accountable to the other, and none presuming that their own own private interpretations could negate the rest of the Church.
That requires extraordinary faith... plus discipline and study. Those who lack any of those requirements will dismiss all scholarship and therefore be unable to draw persons to Christ as He charged the Church to do.
You may draw some to the Bible, but the Bible is not Christ. You may draw them to legalism, but legalism is not Christ.
The teachings of the ancient and undivided Church are not Christ, either, but they are the fullest expression of what He taught and desires for us-- but you would not learn them-- and accuse, berate, and abuse those who do.
Christianity is a broad and deep faith, while some show only a familiarity with the Bible-- estranged from the discussion of the much greater, much richer fullness of the faith.
It frightens you only because it is unknown to you-- but that is your choice. The Apostles knew it, and their successors knew it-- and it was dangerous for them, too. As you see, it is dangerous for non-Fundamentalists to study it as well... but that, too, is by your choice.