My band has been working on a song on and off lately. The other day we really started to get some good progress done on the instrumental portion. However, we don't have many lyrics finished, but we do have a concept, which is that song is talking about war in other nations. It's not preachy and political though . I'm our lead guitarist and I've been given a good amount of creative control, and I'm working on tracking the demo since I've got most of the instrumental down, but I can't write lyrics for the life of me, which I usually could do >.>
Any advice on how to come up with some lines?
Dont try to find the right lyrics right off the bat, start by writing everything you can think off, even the most simple lines, they might not make alot of sense all of them, and they certainly wont be all good.. But get it all out, don't be picky and don't think about it too much..

Afterwards look it through, look for anything that can be used, if you've written down alot, you might have a few lines that could work, or a few ideas that can be used, even if you need to flesh em out.. You might not always get a full song from this, but often you have a good start, and if nothing else you will have a more specific idea of what it is that your after
Songwriting and Lyrics has a sub-forum where you can talk about this kind of thing more freely. This area here is really dedicated only for actual writing.