The fruit of righteousness is expected of all Christians, and rightly so. This comes through our Lord Jesus Christ who is our life. Our union with Christ, and the work of the Holy Spirit in us is what brings glory and praise to God. Such fruit does not come from efforts on our part to be a certain kind of person or to accomplish notable spiritual things. The righteousness of Christ that has been imputed to us makes possible that which is beyond our human limitations.
Filled with the fruit of righteousness indicates that abounding love brings precise knowledge, moral discernment, approval of things that are excellent, resulting in flawless purity. That is not in ourselves but is how God sees us because of our standing in Christ. That in turn, brings in a “bumper crop” of righteousness (filled) which is the goal of all Christian activity. That results in recognition and homage of the holiness of our God who has redeemed us.