Except the Bible itself shows that the Church, through the gathered Apostles and Presbyters, speaks with the authority of the Holy Spirit. See Acts 15. If the Bible attests that that authority existed once then it continues to exist today. Peace.
Yes, the Holy Spirit continues to work through the ekklesia, the church, the body of believers. Your argument presumes apostolic succession which is not supported in the New Testamemt. God can call anyone to serve Him as He did with Paul.