Gospel is only proclamation that should be in Christian pulpits. Every sermon must serve in building Jesus' Church. For test's faith in that Gospel.
There are cults in world today, with schemes for humanity's social improvement. They all are trash when it comes to question: What must I do to be saved? For this there's only one answer.
They that believe and are baptized shall be saved. Faith in Jesus through Gospel and accepting of benefits of Christ's salvation through Baptism, that's only way to become sure of bliss.
Jesus' words impress. Where there's no faith in his salvation, damnation will follow.