The Greek word for angel in the New Testament is aggelios. They both mean messenger. The most frequent dutie of a angel. In the beginning there was God. Then God created angels.
Angels have superhuman knowledge.
They know more than people, but God is only omniscient. We can be certain that God's holy angels use their knowledge for our good. The angels would have access to the presence of God in the third heaven. They Worship God. In Revelation 4 we catch a glimpse of the ceaseless worship of God by the angels.