In this verse, Paul extends a blessing of peace and mercy to those who adhere to the principles he has been advocating throughout his letter. The 'rule' he mentions is the life of faith and love, as opposed to a life bound by the law. This is a central theme in his teachings, emphasizing that faith in Christ and love for one another fulfill the law's true intent.
The phrase 'the Israel of God' is significant. It suggests a spiritual community that transcends traditional ethnic or national boundaries. Paul is likely referring to all believers, both Jew and Gentile, who are united in faith. This reflects the New Testament understanding that the true people of God are defined not by ethnic lineage but by their relationship with Christ.
This verse encourages believers to find their identity in their faith and to live in harmony with others who share this spiritual journey. It is a call to embrace the peace and mercy that come from God, fostering a community that reflects these divine qualities.