The Day of Atonement; Why Are You Here?

What is the Day of Atonement, and how does the meaning of this day fit the scheme of the other holy days?

Dan Miller was raised in the Amish community in Holmes County Ohio, along with his wife, Martha.  They came into the church after they were married, being baptized in 1986.  He is a self taught engineer and has owned and run a manufacturing company amongst the Amish community since then.  The Sabbath was the key doctrine God used to call them, and they were led to WWCG and then United through their obedience.

Dan and Martha were ordained as deacon and deaconness for the Cambridge, Ohio congregation in 2008. Dan was ordained as an elder for the Cambridge congregation in 2012, and they both serve the North Canton, Ohio congregation today.  They have 3 children and 5 grandchildren.