It means we need to bring the good news of the Gospel of Christ to ALL.
The Good News is for all, and Christ told us to bring it to every people and nation. So what is the Gospel message?
It is the single most important bridge between man and God, recognizing that we cannot wash away our own sins and repair the gulf that separates us from our Creator. Only through belief in Christ and repentance can we be declared guiltless of our sin through the Grace of Christ and be saved from Hell itself.
"The time is fulfilled, and the kingdom of God is at hand; repent and believe in the gospel.”
Mark 1:15
Jesus spoke more times in the 4 Gospels about Hell than He did about Heaven. Jesus did not compromise.
Notice that Christ mentioned repentance. Without repentance from our past sinful lifestyles, thoughts, behaviors, and actions - our new commitment to God is a false one. Sin can NEVER be negotiated with - God does not tolerate compromise with His Truth.
Jesus said every jot and tittle of the Law would be fulfilled. Jesus told people what they did not want to hear. Jesus did not go along to get along. Jesus constantly upheld the authority of Scripture.
The pope is not doing what Christ commanded, therefore, the pope is not spreading the true Gospel.