The Heavenly Hosts are the Holy Angels of God: the Seraphim, Cherubim, Thrones, Dominions, Powers, Authorities, Principalities, Archangels, Angels.
There were originally 10 Ranks of Holy Angels, Lucifer being the leader of one of those. Monastics now take the place of the 10th Rank of Angels, for they live like Angels in the flesh, because of their way of life and closeness to God.
The Divine Liturgy and the Holy Angels
About The Cherubic Hymn: An offertory Hymn sung during the transfer of the Bread and Wine to the Altar, the Cherubic Hymn invokes the Eternal Liturgy of the Angels who encircle the Throne of God…
“Let us who Mystically represent the Cherubim and who sing the Thrice Holy Hymn to the Life-Giving Trinity, now lay aside all Earthly cares that we may receive the King of All. Invisibly escorted by the Angelic Orders, Alleluia Alleluia Alleluia.”
Saint Iakovos Tsalikis could see the presence of the Angels.
Saint Moses the Ethiopian received courage from the Angels
It happened that Abba Moses was struggling with the temptation of fornication. Unable to stay any longer in the Cell, he went and told Abba Isidore. The old man exhorted him to return to his Cell. But he refused, saying, ‘Abba, I cannot.’ Then Abba Isidore took Moses out onto the terrace and said to him, ‘Look towards the West.’ He looked and saw hordes of demons flying about and making a noise before launching an attack. Then Abba Isidore said to him, ‘Look towards the East.’ He turned and saw an innumerable multitude of Holy Angels shining with Glory. Abba Isidore said, ‘See, these are sent by the Lord to the Saints to bring them help, while those in the West fight against them. Those who are with us are more in number than they are.’ Then Abba Moses gave thanks to God, plucked up courage, and returned to his cell.
“When a child smiles in a dream, an Angel plays with him.” – Saint Seraphim of Sarov