Doomsday religious groups have come and gone over the centuries and will continue to do so. It's bad enough that gullible followers give up jobs, school and life savings to follow misguided iconic figures who lead them not to the Promised Land, but to disillusionment. Such embarrassing spectacles also hurt the reputation of the followers of Christ overall, even those who are mature, stable and know better than to believe such rantings.
Harold Camping's declaration that May 21st would herald the rapture followed by the end of the world was brassy in its certitude, stating on thousands of billboards "the Bible guarantees it". Then there was this on his website:
Indeed, in the face of all of this incredible information, how can anyone dare to dispute with the Bible concerning the absolute truth that the beginning of the Day of Judgment together with the Rapture will occur on May 21, 2011.
Well! How can we dare to dispute the Bible? But that's not the question. The enormous flaw in this thinking is that disputing with the Bible wasn't at issue; it was disputing Harold Camping's really bad interpretation of the Bible. And it was atrociously bad interpretation; a labrinth of dates, numbers, math equations and huge assumptions. There are many biblical doctrines that still are unresolved in the thinking of biblical scholars after two millenia of study and debate, yet Camping supposed that he had aced them all regarding the most anticipated event in escatology. Far greater scholars have spent lifetimes of study and realized in humility that they only "see through a glass darkly".
Recall too that the religious leadership at the time of Christ believed that they had the coming of Messiah all figured out from the works of the prophets. When Jesus did not fit their interpretation of prophetic text regarding the Messiah, they plotted against Him and had Him crucified by their Roman overseers.
Gallileo was placed under house arrest by the Inquisition because his scientific work brought into question the church's interpretation of the Bible verses that refer to the "rising" and "setting" of the sun and of it "standing still" in the book of Joshua. From these descriptions the church held that the earth was the center of the universe and that the sun rotated around the earth. Gallileo believed that the scriptures were the Word of God and therefore were not wrong, yet his observations and mathematics showed that the earth rotated the sun. He held that the church's interpretation of scripture was wrong: those expressions were merely colloquialisms to describe what the sun looked like approaching morning and evening, not the actual mechanism of its movement.
Thus does poor interpretation, often mingled with a strong dose of pride, spawn bad representation of the Christian faith. The religious leadership of Jesus' time, convinced they had the one and only correct interpretation of the prophets' works, crucified Jesus not because He violated scripture, but because He violated their interpretation of the scripture. The same can be said of the atrocities of the Inquisition. The doomsday silliness of the Harold Campings of the world also are rooted in the same "my interpretation is right, case closed" mentality. All of them committed the error of dogmatically placing their commentary on scripture on par with scripture itself.
Another by product of this will be that fresh scorn will be heaped upon the Christian faith and all religions by the sneering likes of today's proselytizing atheists. In dishing out ridicule they commit the same fatal conceit: declaring emphatically that there is no God, period. Their interpretation of scientific data leaves no room for God and is absolute and infallible, case closed. The Camping debacle just proves to them that all religious believers are superstitious rubes. Radical atheists mock the Christian faith by committing the same error themselves, because prideful dogmatism is not constrained to the church.
An analogy I've cited before is that I work for an excellent company, selling an excellent service. The majority of the employees do excellent, professional work. But if one employee does a poor job representing the company to customers or to the public, it reflects badly on the company as a whole. The work of all the other fine employees are not what the offended customer or public sees. Their view of the company is shaped by the misrepresentation of the one bad apple.
So it is with Christianity. For every self appointed prophet, for every smarmy televangelist, for every pedophile priest there are tens of thousands of humble pastors, brilliant scholars and selfless lay workers who humbly serve in the garden of the Lord, but whom the world never perceives or acknowledges, because the charlatans in their midst cause them shame. The life savings forfeited by a misguided follower of Harold Camping represent temporal material loss. The value of the souls left adrift because bad behavior by Christians repelled them from the joy of God's redemptive love is incalculable.