Your question, Why are we told to fear God when perfect love casts out all fear? (1 John 4:18) If you read verse 17 with 18 you will get a better understanding of what John was talking about. 1 John 4:17 “Herein is our love made perfect, that we may have boldness in the day of judgment: because as he is, so are we in this world. There is no fear in love; but perfect love casteth out fear: because fear hath torment. He that feareth is not made perfect in love. We love him, because he first loved us.” Those who are made perfect in the Love of God have no fear of the judgment to come. The Love that God puts in your heart brings you into the knowledge and understanding of your standing in the Lord. This love gives you confidence of the salvation that has been given to you through Christ. Proverbs 14:26 “In the fear of the LORD is strong confidence: and his children shall have a place of refuge. The fear of the LORD is a fountain of life, to depart from the snares of death. The love that makes you perfect is one of the fruits of the Holy Spirit that the Lord has bestowed upon you. This love dispels all fears of the judgment that awaits. This is what John was referring to. There are two types of the fear of the Lord. One type that a person will experience in their lifetime is when they are lost. Whenever someone hears the gospel and its truth is revealed to them, they tremble with fear, knowing they are condemned in the eyes of God. They realize now that they will suffer the punishment God has in store for them. This is why it’s important to preach the gospel unto the Lost. When a person turns to the Lord he is given his Love to cast the fear of judgment from him. Should we as Christian’s fear the Lord. Absolutely! But it is a reverence fear and not a condemning fear. In this life, a father corrects his children when they disobey him. Similarly, our Heavenly Father will correct his children. (See comment for the rest)