The altar in the church illustrates the presence of a triune God in the midst of the congregation. When kneeling on the semicircular altar, one can imagine it as continuing on the other side of the boundary between life and death. In this way, those who have already passed into eternity also participate in prayer and communion at the altar. In architecture, the apse or apsidal vault is the circular end of a church with a semi-dome-shaped roof. The apse of Kallio Church is visible from the outside of the building as an arched protrusion. The laurel wreaths on the arched windows of the apse, in turn, depict Christ's suffering, love and victory over death.