While in principle there should be no "sacred" version of the song, the reality is that there often is. Example:
"Everlasting God" - in my circle everyone thinks of Lincoln Brewster. But it was written by Brenton Brown, and I personally like the original version. It's a totally different groove than Lincoln's and, to me, Benton's matches the lyrics better. But... every time we play it, I get to try and channel Lincoln's leads and his solo (not so well on the solo, but I am asked to get as close as I can).
I'm not sure why we need to include someone's solo, but I've been told it helps people "recognize the song better". Seriously though, me hacking Brewster's Everlasting God solo is probably not helping anyone recognize the song. I would rather play my own if there is a spot for a solo. I understand the importance of signature riffs, and copping certain tones and effects. I actually enjoy the challenge there and it feels great to nail something. But in general I would rather just play what I feel. Believe me, that is not as dangerous as it sounds. I am not interested in wanking away up there for the benefit of my own ego. In fact, my playing is led by the same Holy Spirit that inspired the original authors to write the songs.