John writes a near chiastic structure (a writing style that uses a unique repetition pattern for clarification and emphasis) in 1 John 5:1-4 (see Smalley), stressing that faith or rebirth necessarily expresses itself in obedience:
John emphasizes that believers express love for God and for his children by obeying his commands.
So, love for God's people is defined in terms of obedience to the commands of God. All of God's commands were designed to give proper honor to God and to his people made in his image. Therefore, believers are not left to speculate as to what it means to love others. Following the commands of God (e.g., keeping the Sabbath, not stealing, and so forth) is the sure way to demonstrate love for others. WCF 13.3; 14.3; BC 10.
By obeying God's commands, a person shows that they love God and love his children. This command to love God and one another is not as burdensome as a life of hate. Those who are born of God share his likeness, and find ultimate delight in doing his will, despite the sacrifices that love may require.