The Floris United Methodist Church in Herndon will hold a candlelight vigil for the family of four found dead Tuesday in their suburban Fairfax County home.
The Peterson family was found by police after work colleagues called authorities when one of the parents did not show up to work.
A source familiar with the investigation called it an apparent murder-suicide.
(Read more about the deaths)
"Everyone is feeling a great deal of grief over this loss and are searching for answers that are not known at this time," Reverend Tom Berlin said in a statement to church members.
Police entered the home around noon Tuesday and found the four bodies -- Albert and Kathie Peterson and their two sons, Matt, a sophomore at Westfield High School, and Chris, a Rachel Carson Middle School student.
(See more photographs from the crime scene)
The Peterson attended the Floris United Methodist Church, where the Chris recently attended a event with the student ministry.
The vigil is scheduled at 7:30 p.m. Wednesday at the church at 13600 Frying Pan Road In Herndon.