Conversation so far:
What is the Seventh-day Adventist about with their connection to the archangel, Michael?
Seventh-day Adventists, believe that Michael is but one of the many titles applied to the Son of God, the second person of the Godhead.
How was the archangel, Michael created?
According to Adventist theology, Michael was considered the eternal Word, and not a created being or created angel, and the one by whom all things were created.

Question: How long have they been around for?
Self-contained rewrite: How long have Seventh-day Adventists been around for?