I love this thread! I can relate to all these feelings.
I too am a (very liberal-minded) Christian. I mean, I guess I'd have to be to... be a Christian medium. Haha!
Though the Bible says we shouldn't practice spirit communication, I try to find the rationale behind that line of reasoning. I personally feel that, in Biblical times, they felt spirit communication challenged and distracted from a relationship with the *one* holy spirit -- not that you shouldn't do it at all but that you shouldn't let it override that relationship with God and the teachings of Jesus. That's simply MY loose Biblical translation...
Anyway... to get to my point... I'm so long-winded!
What feels right to me is that, the Holy Spirit (or God, or the power of the Universe -- whatever you feel it to be) is like an umbrella, or maybe better thought of as an interconnectedness -- the life force that connects us all.
From what I've seen in my meditations and felt from my spirit guides, spirit communication is just a branch of that Holy Spirit, a part of it. Spirit guides are my friends, just like my friends who are alive.
So, it would make sense that you
feel both guides and the Holy Spirit, or that you experience both differently.
I try to take in all spirit messages as if I'm a journalist conducting an interview. I jot down all the information I receive and I try to assess it without attachment, without emotion. Then, I apply it to my life or give the messages to others.
Of course, when I get messages from loved ones, it's harder to stay detached. I once asked a close family member (who's passed on) a question about what I should do. I was completely overwhelmed about a volunteer project I was taking on, and all I wanted to do was dedicate time dwelling on the relationship with this person who I deeply missed.
I was shown a series of visions, where my loved one showed me taking all the emotions of missing him, converting them to strength, and putting them into this new project (a volunteer effort for a family in my community). He said, "The best way to remember me or GIVE a gift to me is to give a gift to someone else, in this case the community." He told me he was now a part of all things, an integral part of the Holy Spirit, so that giving to others WAS essentially giving back to HIM.
The message was SO clear and beautiful that I broke down into tears, knew what I needed to do, and put all my energy into that volunteer project. I now do it every year at Christmas time in his memory. I still miss him, but I feel his presence every time I do something kind for someone else.
Okay, long story... but I hope my experience helps you understand yours!