Soldiers are trained to ignore the internal conflicts and follow orders.
True, most people, christians or not, would hesitate to kill another person without some form of training. But, there are different levels of internal conflict. Following the order to kill a foreigner, while deployed outside the country, doesn't present the same conflict that following the order to kill citizens of your own country would.
If a soldier will kill people under orders, what makes you think they'd hesitate to take away someone's guns when ordered to do so?
Do you understand the concept of legal and illegal order? The Uniform Code of Military Justice (which is a sub-set of United States federal law, not some seperate guidelines invented by the military), Title 10 - Subtitle A - Part II - Chapter 47 - Subchapter X - section 892 provides for punishment of soldiers who fail to carry out lawful orders. There is no requirement to carry out illegal orders, and soldiers from private to general have been prosecuted for issuing or carrying out illegal orders.
I expect that some of them would attempt to carry out that order. I also expect that they would face resistance from others within their ranks that understand the ramifications of such an action. Those being, we are now initiating an armed takeover of the country that we signed up to defend, and going against some of the foundational elements of that country.
It's no different than a gun nut saying in one breath that he "supports the troops" and in the next saying he's going to shoot any soldiers who come to take away his guns.
Why do you keep going to the "Support our troops = believes in 2nd amendment rights" story? Why would you think that "supports troops in (sorta, kinda) legal actions in a foreign country" is the same as "supports troops when they are taking illegal action in the US"? Those are certainly different scenarios.
Your fantasies about citizen-soldiers are nothing more than dreams. If the federal government ever decided to take away your guns, they won't have any problem getting soldiers to do it, and you'll be massively outgunned.
Wow, I though I was a pessimist. Hopefully I can keep dreaming, and don't have to find out how this plays out. I don't know what your definition of "won't have any problem" is, but I guess we'll have to agree-to-disagree about the level of commitment to the rule of law and the constitution that is present in the armed forces. I'm sure it's not 0% would or 0% would not obey those orders, and based on what the actual numbers are, so goes the chances of such a thing happening or not.
For the sake of discussion, what does it look like when 30% of the soldiers given these orders refuse them, and take action to keep them from being implemented. At the same time, approximately 30% of US households own firearms, at a rate of more than 1 per household. I don't think that is "won't have any problem" territory. Sure, some of those people will willfully turn them over, but lets talk about those who don't. Are you suggesting that troops with rocket launchers, or an air strike, are going to be called against some person or group that refuses to turn over their firearms? Now you're getting into Civil War territory, and the only people wishing for that are far out on the fringe. Being "massively outgunned" means less than you might think, see US vs. North Vietnam, USSR vs. Afganistan, Israel vs. Palestinians . You have to factor in the "will to fight". There would be doubt in the minds of soldiers, and much less in their opponents.