There were angels that appeared throughout the Left Behind books that provided deliverance and protection for the believers in Christ during the Tribulation period and also during the Millennial Kingdom. One of them was named Anis, who appeared during Buck Williams' attempt to smuggle Tsion Ben-Judah out of the country of Israel to the safe house next to the New Hope Village Church, when Buck and Chaim Rosenzweig visited the empty tomb of Jesus Christ after Leonardo Fortunato had incinerated Hattie Durham, and when Rayford Steele was kidnapped by members of The Only Light.
Angels are shown to wield great powers, but have few if any desires or ambitions on their own -- in Kingdom Come: The Final Victory, they are described as "not qualified as guests" during the Feast of the Bridegroom at the beginning of the Millennial Kingdom. Powers shown include selective invisibility, enough telekinesis to remotely open cell doors, and the ability to utter a soporific benison that can cause unprepared humans to fall asleep instantly. Presumably, they are impervious or resistant to projectile weapons. In the Bible, they are also shown capable of making limbs go numb with a touch.