I do not condemn them personally I condemn their Hell fire teachings and warn them of the fires of Hell where they are headed and Jesus made it quite clear about the doom of those that teach another gospel read Jude and Gal 1:8-9. Unitarian Universalists teach another gospel and united methodists corrupt the gospel with their progressive gay theology.
Unitarian Universalists don't really teach another gospel so much as they don't teach any gospel at all. They're another (very loosely defined) religion, really, with a few people in the association claiming some affiliation with Christianity (typically in a very liberal, very loose sense). Writing to them would be the equivalent of writing to your local Buddhist congregation. You can do it, but it's not the same as writing to a church that even claims to be Christian at any level.
The United Methodists are divided (pun semi-intended) on the issue you mentioned. I know of ministers strongly on opposite sides of the issue, even as the official Book of Discipline holds the more conservative viewpoint. It's church-by-church in the UMC.