Angels appear in the Bible from the beginning to the end, from the Book of Genesis to the Book of Revelation. The Bible is our best source of knowledge about angels - for example, Psalms 91:11, Matthew 18:10 and Acts 12:15 indicate humans have guardian angels.
Angels announce the birth of Jesus to the shepherds [Luke 2:14], minister to Christ after his temptation in the desert [Matthew 4:11], comforted Jesus in his agony in the garden [Luke 22:43], and appear to announce his resurrection from the dead [John 20:12] . According to Jesus, the angels of little ones continually behold the face of the Father [Matthew 18:10]; angels will come with Him on the Day of Judgement [Matthew 24:31], and the angels will separate the wicked from the just on the last day [Matthew 13:49], although they do not know the day of Judgement [Mark 13:32]; and the children of the resurrection will be equal to the angels [Luke 20:34].
Michael is one of the leading angels, and is considered "Prince" of the heavenly hosts, and the Guardian Angel of Persia [Daniel 10:13]. He is the only one in the Bible referred to as an Archangel [Jude 1:9], and serves a major role in Chapter 12 of the Book of Revelation. The angel Gabriel first appears in a vision to Daniel [Daniel 8:16], but is best known for the Annunciation to Mary that she would be the Mother of Jesus [Luke 1:26-38]. Revelation 8:1-2 also refer to the seven angels who stand before the Lord.
