The writer of the Book of Hebrews states that God knows ahead of time who will receive the gift of salvation. Because of His foreknowledge, He assigns an angel to them, even before they commit their lives to Christ. The creator God, the Lord of all the Earth, lives outside of time and acts inside of time from what He knows you will do with the gift of God—the gift of eternal life in Christ Jesus. If you are a believer, an angel of God has been assigned to you. You might have noticed that the passage following says that angels are sent to those who will inherit salvation—future tense.
Are not all angels ministering spirits sent to serve those who will inherit salvation? (Hebrews 1:14).
For He will give His angels charge concerning you, to guard you in all your ways (Psalm 91:11).
The angel sent to you is a ministering (serving) spirit sent to serve you. The Bible has many instances of angels serving God and His people down through the ages. We don’t talk to the angels or reach out to them—we speak to God about what we are going through, and He instructs His angels on what to do. Of course, there are evil angels as well. Satan is an evil angel that heads up an army of demonic spirits opposing God and seeking to corrupt and destroy God's greatest creation—Man. Most of the time, these evil entities are not seen, but God has occasionally let men see how many are on our side against the demonic spirits.
For instance, in the Old Testament book of 2 Kings, there is the story of a king reigning in Aram who was angry because his actions and intentions were somehow being made known to the armies of Israel. He could not understand how Israel knew his plans (2 Kings 6:8-10). He thought he had a spy among his leaders. His problem was that Israel had a man of God, Elisha, who lived in such a way that he was able, by the Spirit of God, to know the words that the King of Aram spoke in secret to his generals (2 Kings 6:11-12). Elisha had developed a powerful prayer life and was acutely aware of the unseen realm, for the Lord revealed to him what Israel's enemies were doing. When the King of Aram found out about Elisha's gift, he was so enraged that he sent his army to the town where Elisha lived, hoping to kill or capture him:
14Then he sent horses and chariots and a strong force there. They went by night and surrounded the city. 15When the servant of the man of God got up and went out early the next morning, an army with horses and chariots had surrounded the city. "Oh, my lord, what shall we do?" the servant asked. 16"Don't be afraid," the prophet answered. "Those who are with us are more than those who are with them" 17And Elisha prayed, "O LORD, open his eyes so he may see." Then the LORD opened the servant's eyes, and he looked and saw the hills full of horses and chariots of fire all around Elisha. 18As the enemy came down toward him, Elisha prayed to the LORD, "Strike these people with blindness." So he struck them with blindness, as Elisha had asked (2 Kings 6:14-18).
When Elisha’s servant looked at the size of Aram’s army around, and about the city, he began to lose heart. Things looked hopeless when seen only from an earthly perspective. But all was not as it seemed. There were spiritual forces around Elisha and his servant, to which the young novice to the things of God was unaware. Elisha prayed that God would open his servant's eyes to the unseen angels in the spiritual realm around them. All of a sudden, at the prayer of Elisha, he saw beyond this physical world the reality of the spiritual forces of God previously hidden from him, angelic beings much more powerful than the army of Aram. He saw the armies of heaven protecting and surrounding the prophet of God, available to serve him in whatever way the prophet prayed. One display of God's power defeated all the enemies of Israel at the prayer of Elisha. As servants of the Living God, we also have angelic hosts protecting us. In whatever you are going through this day, call upon the Lord to help you. Whosoever shall call upon the name of the Lord shall be saved (delivered) (Joel 2:32). Keith Thomas