Luke 2:13-14
Then suddenly there appeared with the angel a large number of the heavenly "army" [i.e., of angels], who were praising God and saying,
Ephesians 3:10
This was done so that now God's many-sided wisdom could be made known through the church, to the rulers and authorities in the heavenly realms [Note: "Heavenly realms" here refers to the world around us, where these angelic beings (good or bad) view the unfolding of God's wonderful plan],
Revelation 5:11-14
Then I looked, and heard the voice of many angels surrounding the throne and the living beings and elders. They numbered in the tens of thousands, and thousands and thousands [more]. [Note: The Greek says "myriads of myriads"].
Revelation 7:9
After seeing [all] these things, I looked and there [I saw] a huge crowd, which no one could count, from every nation, and tribe, and race, and language group standing in front of the throne [of God] and in front of the Lamb. They were dressed in white robes and had palm tree branches in their hands.