Longtime clean vocalist and drummer Aaron Gillespie will depart Underoath at the conclusion of their ongoing European tour. The band made this statement:

We are taking this opportunity to sadly inform you the six of us have decided at the end of the current european tour, Aaron will no longer be playing in Underoath. This was not a decision made in haste but a thought out and prayed upon group agreement. It in no way effects any of the shows left on this tour. They will still be our best efforts and enjoyable experiences for all. For the future, Aaron will be pursuing other musical and ministry endeavors. As for the rest of us we will continue to work hard on the new Underoath record.

Gillespie was the only member left from the founding of the band in 1997. He will likely continue on with his rock project, The Almost.
Source Longtime clean vocalist and drummer Aaron Gillespie will depart Underoath at the conclusion of their ongoing European tour. The band made this statement:

We are taking this opportunity to sadly inform you the six of us have decided at the end of the current european tour, Aaron will no longer be playing in Underoath. This was not a decision made in haste but a thought out and prayed upon group agreement. It in no way effects any of the shows left on this tour. They will still be our best efforts and enjoyable experiences for all. For the future, Aaron will be pursuing other musical and ministry endeavors. As for the rest of us we will continue to work hard on the new Underoath record.

Gillespie was the only member left from the founding of the band in 1997. He will likely continue on with his rock project, The Almost.
Source