I've been with an immigrant for five years and we are planning on getting married. We have a problem he does not have any ID. What can we do?

Move to their home country...

Because marrying one will NOT grant them any ID or right to live here by virtue of marriage. They would still be just as illegal as they were before, and nothing would would change for them.

They still might NEVER be able to get legal and would still be subjuect to deportation.

What do you mean he "does not have any ID"? What do you mean by "ID"? When you say "ID" I think of something like driver's license, passport, college ID, library card, etc. which have nothing to do with immigration. I don't think that you need an ID to get married.

Do you mean he is not legally here? If so, what is your status? (U.S. citizen / permanent resident / other immigrant / visitor / etc. ) Are you asking if you can apply for him to immigrate legally? If so, it is very important to know how he got here. Did he enter legally (e.g. on a visa) but then overstayed? Or did he e.g. jump the border? If the former, it should be fairly straightforward to apply to adjust status as your spouse if you are a U.S. citizen. If the latter, it is much harder and you should get an immigration lawyer.

What do you mean he "does not have any ID"? What do you mean by "ID"? When you say "ID" I think of something like driver's license, passport, college ID, library card, etc., which have nothing to do with immigration. I don't think that you need an ID to get married.

Do you mean he is not legally here? If so, what is your status? (U.S. citizen / permanent resident / other immigrant / visitor / etc.?) Are you asking if you can apply for him to immigrate legally? If so, it is very important to know how he got here. Did he enter legally (e.g. on a visa) but then overstayed? Or did he e.g. jump the border? If the former, it should be fairly straightforward to apply to adjust status as your spouse if you are a U.S. citizen. If the latter, it is much harder and you should get an immigration lawyer.

If they jumped the border it's a given they will have to leave the country before they can even entertain making application... even on an expired VISA. I've known too many people in both situations that had to leave the country to even begin to deal with this...

There is no easy or certain result... even with a lawyer.

I know one that after years of trying and tens of thousands in legal fees... was told his wife would NEVER be given a green card. (and she has a clean criminal record AND a kid)

If they jumped the border its a given they will have to leave the country before they can even entertain making application...even on an expired VISA. I've known too many people in both situations that had to leave the country to even begin to deal with this...

There is no easy or certain result.....even with a lawyer.

I know one that after years of trying and tens of thousands in legal fees...was told his wife would NEVER be given a green card. (and she has a clean criminal record AND a kid)

If he entered the U.S. legally, but his status expired, and she is a U.S. citizen, he is eligible to adjust status in the U.S.

If he entered the U.S. illegally (jumped the border), he will have to leave the U.S. for some step of the adjustment of status, but he can apply in the U.S. for a hardship waiver of the 3- or 10-year bar to entry, if there is one.

If he entered the U.S. legally, but his status expired, and she is a U.S. citizen, he is eligible to adjust status in the U.S.

If he entered the U.S. illegally (jumped the border), he will have to leave the U.S. for some step of the adjustment of status, but he can apply in the U.S. for a hardship waiver of the 3- or 10-year bar to entry, if there is one.
Really... (trying to get a legal visitor status changed to an immigrations status for my wife)because I've been there myself with my wife and that is so very contrary to what I found out... even before her legal status lapsed here... and I had to leave the country with her to get anything changed... and that was not what some flunky clerk told me (trust me the INS offices are full of those, or at least the two I dealt with in two states)... I got that Information through connections I had in the government... and even then it took those connections to get through the very abundant red tape. And that was after 2 years of trying and getting nowhere myself and costing thousands I didn't really have.

Without that help I doubt it would have gotten done anytime soon after that if at all.

And the other person I know... his wife was illegal... never arrested... and even if she went back.. they told them she would never be issued an immigrant visa much less ever get a green card... despite having a USA born child. So she is in constant risk of being deported at any time.

So while its possible... its also possible it will never result in legal status...

He needs a passport.

The immigrant will have a passport, if they have lost their passport and visa, they will need to go to their embassy to get that replaced.