What kind of preaching was Jesus talking about in Mathew 24:14? It seems to me that Jesus wanted Christians to preach the hope of the resurrection to mankind. Nowhere in the Bible, does it say that Christians were to preach their own interpretation of Bible prophecy as the WTS does today.
The faith of the first century Christians was not based on their interpretations of the old testament. It was based on the knowledge that eternal life can be obtained through faith in Jesus -and that's all there was to it. Jesus did not want his followers to worry about when where and how things were to occur. Even when he did provide simple explanations, such truths could not be understood even by those closest to him.
Could the early congregations have survived if the so called governing body had confused them with a flood of theories and misleading predictions? Not at all. That's why their command was simple, to preach the gospel of the resurrection through faith in Jesus. It was a simple teaching, but it was one that could be easily understood unlike the pagan teaching of the time.
Having faith in Jesus and having faith in the interpretations of an organization are two very different things. Having faith in Jesus means that you have believe in the future fulfillment of his promises. Having faith in the interpretations of an organization means that you rely on the imperfect understanding of man.