I have all of Glass Harp's CDs. One note, they are not a Christian band. I believe they came out before Phil was a Christian. Lyrically, they are not any "bad" songs, but they are not like Phil's early works which were very Christ centered.
Musically, they are very laid back and just really cool sounding early 70's prog rock. Great guitar work and really great to just kick back and listen. The albums Glass Harp, Synergy, and It Makes Me Glad were all re-issued a couple of years ago and are quite easy to get. The sound is great on them. I have the original Line Records German CD releases and the re-issues and they are both exceptional sound quality. The difference is that each of the re-issues has an extra song not on the originals (I had the originals when the re-issues came along).