Angels haven't always existed; God created them and He did it long before He made the world. God asked Job, "Where were you when I laid the earth's foundation ... and all the angels shouted for joy?" (Job 38:4,7).
Why did God create the angels? The Bible says He created them to be His servants and carry out His will. We can barely imagine what this must involve, but every time we meet them in the Bible God's angels are doing something He has told them to do. Only rarely do they take visible form; they are spiritual beings, and most of their work is unseen and unknown by us. They have a special responsibility to watch over God's people; the Bible says that God "will command his angels concerning you to guard you in all your ways" (Psalm 91:11).
At the same time, the Bible makes it clear that we aren't to worship angels or focus undue attention on them. One of the errors the Bible warns us against is "the worship of angels" (Colossians 2:18). Why is this? The reason is because only Christ can forgive us, and our faith is to be in Him alone.
Make sure of your commitment to Christ and trust Him alone for your salvation. Then take comfort in His promise always to be with you. Through His death and resurrection "we have redemption through his blood, the forgiveness of sins" (Ephesians 1:7).