Why is the fear of God the Bible’s definition of love for God?
You may be referring to the fear of the Lord rather than fear of God. Although the Bible talks a tiny bit about fearing God, the word for “fear” does not have the primary meeting of being afraid. The primary meeting of fear when it refers to God or the Lord means to reference and revere God, to be in awe of him.
Further, the fear of the Lord, or the fear of God, is not the basis for the definition for love for God. Jesus tells us that if we love God we will keep his commandments (John 14:15). The best way for us to demonstrate our love for God is through obedience. God’s love for us and our love for him is not based on fear. Perfect love casts out fear (1 John 4:18).
It is true that if we fear the Lord, we revere and honor him for who he is and what he has done for us. So our love as Christians is based on the fear of the Lord, but it is because we worship him. It is not because we have to be afraid of him to love him.
Our love for God is actually based on his love for us, and that he taught us how to love (1 John 4:19). Anyone who is a child of God, a believer in Jesus, doesn’t need to fear God. However, there will come a time when his judgment comes upon this earth. In that time, anyone who does not know him will be afraid of his judgment and wrath.