He emphasized that Jesus did not cease to be God when he became a man, nor did he lose any of his divine attributes when he took on human nature. Furthermore, Gregory asserted that Christ was fully human, including a full human soul. He also proclaimed the eternality of the Holy Spirit, saying that the Holy Spirit's actions were somewhat hidden in the Old Testament but much clearer since the ascension of Jesus into Heaven and the descent of the Holy Spirit at the feast of Pentecost.