Manifestations of the All-Holy Spirit

Regarding the manner in which the Holy Spirit descended upon the disciples, Saint Symeon the New Theologian makes a remark that is most helpful for properly understanding this event. He says that this mode of acting of the Holy Spirit - by means of a loud noise as of a rushing mighty wind, and with tongues of fire - was something unique. The Holy Spirit, he observes, comes very calmly, in the form of spiritual light, and evokes joy. The passage in which he touches upon this point is this:  The power of the Holy Spirit, which is bestowed upon him who loves God and keeps His commandments, does not appear visibly in the form of fire, nor does it come with a loud sound like a violent wind - for this happened only in the time of the Apostles for the sake of the unbelievers. Instead, it is seen spiritually in the form of spiritual light, and comes with all calm and joy. Guide to Byzantine Iconography, Vol. 1, by Constantine Cavarnos