Chairboy,
You've exactly flipped the situation and the issue. First off, we aren't talking about moving from a anti-theistic to a theistic society, the situation, as even the quote I gave is exactly the opposite - we are moving from being what President John Adams called "a moral and religious" people to an explicitly "anti-moral and irreligious" nation.
The problem with that, apart from the fact that our current society can't survive the transition (again to quote Adams: "Our Constitution was made only for a moral and religious people. It is wholly inadequate to the government of any other") is that it also means that the rights of Christians are being eroded and ultimately eliminated. This isn't about establishing a theocracy, or recognizing and establishing one denomination over others - both the US Constitution, and for that matter even the confession of faith of my denomination rule that out*. We are getting to the point where any kind of Christian speech in the public square is legally prevented, while specifically anti-religious, irreligious, or pornographic speech is protected. Most of us forsee a day approaching when merely preaching what Romans 1:18-32 says about "alternate lifestyles" will be termed as illegal hate-speech in this country as it already is in many European nations. From upholding Religion and Piety, we have come to the point where there is a defacto legal jihad being waged against them.
- SEAGOON
*From the Westminster Confession of Faith, Chapter 23.3 (American Revision, 1788) - "Civil magistrates may not assume to themselves the administration of the Word and sacraments; or the power of the keys of the kingdom of heaven; or, in the least, interfere in matters of faith. Yet, as nursing fathers, it is the duty of civil magistrates to protect the church of our common Lord, without giving the preference to any denomination of Christians above the rest, in such a manner that all ecclesiastical persons whatever shall enjoy the full, free, and unquestioned liberty of discharging every part of their sacred functions, without violence or danger. And, as Jesus Christ hath appointed a regular government and discipline in his church, no law of any commonwealth should interfere with, let, or hinder, the due exercise thereof, among the voluntary members of any denomination of Christians, according to their own profession and belief. It is the duty of civil magistrates to protect the person and good name of all their people, in such an effectual manner as that no person be suffered, either upon pretense of religion or of infidelity, to offer any indignity, violence, abuse, or injury to any other person whatsoever: and to take order, that all religious and ecclesiastical assemblies be held without molestation or disturbance."