Paul was born into a Greek Orthodox family.
In the mid-1980s he became a member of the OCA.
He received a Master of Social Work from Wayne State University before studying at St Vladimir' s Seminary, graduating with a Master of Divinity in 1994.
He served in the Diocese of the Midwest - first at St Thomas the Apostle Church in Kokomo, for 11 years, and then at Archangel Michael Church in St Louis for 7 months. In 2007, he was transferred to the Bulgarian Diocese ( OCA) and assigned Dean of St George Cathedral in Toledo.
On [[October 7]], 2014, at the
Diocesan Assembly, he was nominated to fill the vacant seat of Bishop of Chicago and the Midwest.
[http://oca.org/news/headline-news/midwest-diocesan-assembly-nominates-archpriest-paul-gassios-for-vacant-chic Midwest Diocesan Assembly nominates Archpriest Paul Gassios for vacant Chicago See]