First, they need to let the guy go. Religious freedom is something I support even when I do not agree.
However, there are a few people who are willing to go into North Korea or China to proselytize, fully knowing that they would be subject to arrest. I don't know what to think of that other than the USA should support them, mainly because I firmly believe in religious freedom. However, if I were a State Department official debriefing an individual like this, I might very sternly remind them of the effort and expense that led to their freedom. And if they spent years locked up, I certainly would remind them that they undoubtedly knew that when they went there in the first place and did what they did.
I think these guys are working against their own goals. And certainly against my personal lack of belief. So I confess bias.
I think they should get another vocation, one with less ideology and with more consideration for the consequences of their actions.
I want religious freedom. I suspect that they want nothing other than Christian worldwide conversion.