Is fundamentalism within any religion a dangerous thing?
Fundamentalism, when it pertains to anything outside of biblical truth is dangerous. Beliefs of any sort that place the soul of a person in peril of eternal damnation and apart from God's saving grace is fundamentally flawed and should be rejected. This problem can be found in every religion that denounces the basic truths of biblical Christianity. The fundamental truths of biblical Christianity are lifesaving, not dangerous. Religion is faith in a system of belief that is usually manmade. Christianity is about faith -- a belief in and a personal relationship with the Person of Jesus Christ as taught He taught while he was here on earth. The Bible tells us:
"Jesus saith unto him, I am the way, the truth, and the life: no man cometh unto the Father, but by me" (John 14:6).
To reject Jesus is to miss out on heaven and God the Father for all eternity. Instead, it means spending eternity in the lake of fire (the eternal hell) because of unforgiven sin. Jesus proclaimed this about Himself:
"For God so loved the world, that he gave his only begotten Son, that whosoever believeth in him should not perish, but have everlasting life. For God sent not his Son into the world to condemn the world; but that the world through him might be saved. He that believeth on him is not condemned: but he that believeth not is condemned already, because he hath not believed in the name of the only begotten Son of God" (John 3:16-18).
True biblical Christianity is not about religion it is really about having a personal relationship with Jesus Christ and keeping the entire focus on Him and what He did to save all of mankind.