Aware of the spiritual needs of the people of Trumbull, the Bishop made Saint Theresa's the first Catholic Church in town, and dedicated it in honor of Thérèse of Lisieux, the Little Flower of Jesus.

Bishop McAuliffe dedicated the original small white frame church on September 22, 1935, so that Saint Theresa's functioned as a true parish.

The original church was a classic New England colonial design that could seat some four hundred people, and the neighboring McLevy homestead became the parish rectory.

Instruments include a three-manual 38 rank Peragallo pipe organ with 7 additional Walker electronic stops, mainly in the Pedal division.

[6][7] Saint Theresa is home to over thirty social and religious ministries, including Boy Scouts of America Troop 68,[8] Knights of Columbus Council 8013,[9] and charitable outreaches such as the Thomas Merton Center.

[10] Founded in the Parish in 2011, this men's ministry of approximately one hundred twenty members[11] attracted national attention on EWTN.