Romans 15:13-13

¹³ “Now may the God of hope fill you with all joy and peace in believing, so that you will abound in hope by the power of the Holy Spirit.”

Christ is constantly filling His children with the fruit of the Spirit. This would be especially relevant in light of the Jew and Gentile tensions existent in the church of Rome. Instead of judging one another over matters of food and drink, Christians could express joy and peace towards one another. This is the inner kingdom that Paul has been talking about (Romans 14:17).