Prior to his installation as Archbishop of San Fernando, he previously served as fourth bishop of Iba in Zambales from September 1, 2004 to October 27, 2014.

He graduated in college at the Holy Angel University in 1978 before entering the San Carlos Seminary.

His consecrator was then the Apostolic Nuncio to the Philippines, Antonio Franco, while his co-consecrators were Paciano Aniceto and Gaudencio Rosales .

[1] On October 27, 2014, Lavarias succeeded Paciano Aniceto as the latter resigned as Archbishop of San Fernando, Pampanga due to the age limit after being appointed by Pope Francis three months earlier on July 25, 2014.

[2] Due to the departure of Ruperto Santos to become fifth Bishop of Antipolo covering Marikina in Metro Manila and the province of Rizal on July 22, 2023 which ended his term as fourth bishop of Balanga, Lavarias was appointed by Pope Francis as sede vacante apostolic administrator of the Diocese of Balanga where he currently holds the position while awaiting for the installation of Santos' successor as the diocese's fifth bishop.