The Bible makes it clear that God's angels are still very much at work, although their ministry is largely unseen by us. Even when they take human form (as they can do on occasion), they may not be recognized as angels. The author of the book of Hebrews wrote: "Do not forget to entertain strangers, for by so doing some people have entertained angels without knowing it" (Hebrews 13:2).
What do the angels do? Occasionally, God may entrust them with special messages, just as He did when the angel Gabriel told Mary she would become the mother of the Son of God, Jesus Christ (see Luke 1:26-38). I've heard reliable reports of people today who live in countries with no access to the Gospel, but who have come to Christ because of an angelic visitation or vision.
But for the most part the angels have been given the unseen task of watching over God's people and guarding them from spiritual and physical harm. Only in heaven will we realize just how much they did for us. The Bible says, "Are not all angels ministering spirits sent to serve those who will inherit salvation?" (Hebrews 1:14).
We aren't to worship angels or become overly preoccupied with them. But we should thank God for sending them to watch over us, and they should cause us to trust Him more fully every day. Because of them we know our lives are safely in God's hands, and that some day they will take us into His presence forever.