As Catholics we believe the Holy Spirit proceeds from the Father and the Son. What is the Coptic Orthodox church belief concerning this matter?
Our Coptic Church believes that the Holy Spirit proceeds from the Father not from the Father and the Son. This belief was agreed upon by ALL Christians in the Council of Constantinople held in 381 and attended by 150 Bishops. The exact text of the Creed states "And (We believe) in the Holy Spirit, the Lord, the Giver of Life, who proceeds from the Father: who with the Father and the Son together is worshipped and glorified..."
Our Lord Jesus Christ specified, "But when the Helper comes, whom I shall send to you from the Father, the Spirit of truth who proceeds from the Father, He will testify of Me" (John 15:26). The Holy Spirit does come from, and through, the Son, in the sense that the Spirit is sent into the world by the Son. However, the Father is the Unique Source of the Godhead. The Son eternally begotten by the Father, and the Holy Spirit eternally proceeding from the Father, are also equally God. To claim that the Holy Spirit proceeds from the Father and the Son places the Holy Spirit in a state of subordination to the Father and the Son.