I've been invited to a Bible study (on the Revelation to John) held by a local Seventh Day Adventist church. I didn't know much about Adventists until the last year or so. I did gain respect for them after reading Ronald Numbers' book.
Their theology is basically post-trib/pre-mil Baptist. And they are very dedicated to Saturday worship.
Occasionally, the 30,000 denomination statistic comes up (a number which, I believe, counts independent and non-denominational churches each as their own denomination...). I am reminded of something Todd Friel says. Jesus (Matthew 19:8, etc.) said that God allowed divorce because of the hardness of people's hearts. Does God allow denominationalism because of the hardness of our hearts?
I've been reading repeatedly through the book of Romans. And every time I hit chapter 14, I am reminded of this again. Solid Christians must restrict their freedom on the behalf of those who are weaker. The weak and the strong in faith should not judge one another. Let everyone keep these minor issues private to himself.
Hold fast to the essentials, give grace otherwise.