Be not forgetful to entertain strangers: for thereby some have entertained angels unawares. (Hebrews 13:2 KJV)
From the bible, we know that God created angels. (Colossians 1:16-17) We know that angels interact with humans at the behest of God. (Luke 1:26-38) They deliver messages. (Daniel 9:20-23). They fight for territory. (Daniel 10:20). They guard humans (Matthew 18:10) and report to God on the actions of children, anyway (Matt. 18:1-14) and perhaps to individually minister to adult Christians also (Hebrews 1:14). Angels are divided into hierarchies and troops, including both good and evil angels, and special categories such as cherubim, seraphim, and the archangel. They are invisible. (2 Kings 6:17). They look like men sometimes, (Gen 18:1-2) and other times they look like glory (Matthew 28:2-4) and other times they look like metal and lightning (Daniel 10:5-6) and still there are other angels who look completely unusual and beyond description (Revelation 4:6-8). [For the record, with one debatable exception, angels are not biblically described as having any wings]
Surely, it is a blessing that there is a class of created being whom God uses for His glory and for our help. It is a blessing also to think that we may entertain one of them at some point in our lives!
But do not forget, there is another class of angels. There was a rebellion in heaven, and the highest angel, one created to guard the throne itself, tried to vault himself above God and was kicked out of heaven for it. His name is Lucifer, whose title is now the devil, adversary, satan. And even though a third of the multitudes of angels lived with God, and saw His glory and knew His heart, Lucifer was apparently so convincing that they sided with him against God, and so they were kicked out too. (Revelation 12:3-4,9)
Not everything supernatural is from God! If you entertain angels unawares, it may be a good angel sent to minister to you. Or it may be a fallen angel, sent by satan to thwart you, deceive you, or hinder you. ( also 1 Tim.4:1-3; 2 Cor.11:13-15) "And no wonder, for Satan himself masquerades as an angel of light. It is not surprising, then, if his servants masquerade as servants of righteousness. Their end will be what their actions deserve." (2 Corinthians 11:14-15)
If you are reading this before the rapture, Christian and non-believer, be aware that deceit comes in a guise wrapped in a beautiful package. Fallen angels would look just like the glorious angels, as stated above in the Corinthians verse. If you are a Christian, you should be praying daily to receive wisdom, and it will be given to you without reproach. You should be in the Word daily so that you will know the truth from a lie. If you are a non-believer reading this after the rapture, know that your odds of learning the truth have diminished but you can pray to Jesus to forgive you of your sins (if you are truly sorry for your bad acts and thoughts, that is) and He will forgive you. He will send the Holy Spirit to you to help you discern the truth from a lie. Without His help, you are at the mercy of an adversary who can and does 'appear to us unawares' and always for the purpose of destroying us!
NOT EVERYTHING SUPERNATURAL IS FROM GOD! "The coming of the lawless one will be in accordance with the work of Satan displayed in all kinds of counterfeit miracles, signs and wonders," (2 Thessalonians 2:9). Angels might surround you unawares, but YOU should not be unaware of satan and his angels' counterfeiting abilities!