Jesus preached the gospel of the kingdom. Paul preached the gospel of the kingdom. That kingdom was established in 33 AD with the in filling of the Holy Spirit at Pentecost.
1914, Pastor Russell, Rutherford and company, Watchtower Society etc. has nothing to do with the kingdom. The kingdom that was and is established is the church of God which consists of every true believer in Christ Jesus.
Everything else is just counterfeit christianity.