I was a member of the Non-denominational Charismatic Church. I know, it's an oxymoron, but that is how they chose to be addressed. They practiced speaking in tongues, which many denominations do not accept, despite the Bible saying, "Do not forbid speaking in tongues."

When I went through what is believed to be the baptism of the Holy Spirit, which is described in the account of Pentecost, I also spoke in tongues. The funny thing is, no two people seemed to be speaking the same language, even though all were considered to be truly speaking an angelic language. Each person's 'tongues' were unique to them, and often turned into repetitions of the same syllable. This instilled some doubts in me about the nature of speaking in tongues.

What I find interesting is this: I can still speak in tongues if I feel so inclined, despite not being a believer.

You ask a well pointed question that turns one's attention to something seldom considered.