They are to mark the 40th anniversary of the opening of the original Bethany building that took place at the end of May in 1975.
The preachers at the services are to be the Rev David Smith from Ardaragh in County Down who will preach at the morning service, and the Rev John Gray from Bethel in Enniskillen who will be the preacher at the night service.
Both men were former members of the congregation along with three others who went on from the church to become ministers of the Gospel.
Dr Kenneth Elliott and the Rev Darryl Abernethy, ministers of Bethany, will preside at both services.
The former Bethany Gospel Singers and Miss Hannah Mitchell will minister in song at both services.
This anniversary occasion marks the first of four major building projects that the congregation has undertaken during the past 40 years.