Which theological concept was clarified regarding the Holy Spirit during the ecumenical councils?

The clarification regarding the Holy Spirit’s processions and relationship within the Trinity during the ecumenical councils is a foundational aspect of Christian theology, particularly in understanding the nature of God as a Trinity of Father, Son, and Holy Spirit. This was especially emphasized in the Nicene Creed developed in the Councils of Nicaea (325 AD) and Constantinople (381 AD), which articulated that the Holy Spirit proceeds from the Father (and, in Western traditions, from the Son).

This theological development was crucial in affirming the equality and co-eternity of the Holy Spirit with the Father and the Son, which countered various heretical views that either diminished the Holy Spirit's divinity or misrepresented the relationship within the Trinity. The distinct processions of the Holy Spirit also helped in delineating the roles of each Person in the Trinity, contributing to a more robust understanding of Christian doctrine which is vital for proper worship and understanding of the faith.

The other concepts, while related to the Holy Spirit, do not hold the same level of doctrinal significance that was addressed in the councils. For instance, the concept of multiple spirits does not align with mainstream Christian belief, the process of how believers receive the Holy Spirit, while important in a