Eastern Catholic churches affirm the full divinity and personhood of the Holy Spirit, the Third Person of the Trinity, who proceeds from the Father and is worshipped and glorified equally with the Father and the Son. A significant theological and liturgical distinction is that most Byzantine Rite Eastern Catholics recite the Nicene Creed in its original form—'who proceeds from the Father'—without the Latin addition of 'and from the Son' (Filioque).

The Pontifical Council for Promoting Christian Unity clarified in 1995 that the Latin Filioque addition does not contradict the Eastern theological tradition of the Spirit's procession from the Father as the sole Principle. Eastern Catholics remain in communion with Rome while maintaining their traditional Creed, regarding the two formulations as complementary expressions of the same faith rather than contradictory doctrines.