The disciples expected that Christ would "come" as King, with a royal presence, and to remove the Romans and thrown down the corrupt temple, all at the same time and soon! It was a disappointment for them it turned not out that way, but they came to understand we could have an even much better future because of what Jesus had done. Though they also became convinced of the necessity to be prepared for the time that Jesus would return and that each believer could add by his effort of preaching, to bring the time closer.
In the history of Christendom we see many churches which started of as so called cults or so called heretic movements, though many years later they sometimes outgrew their original group and/or became one of the many main churches. Therefore one should be very careful by damning a group or calling ti a cult or sect, when there is not really anything what qualifies it to become called a sect or cult.
Before calling a church or religious group a "cult" or "sect" one should seriously examine and clarify what one means with those qualifications.
Lots of times Christadelphians are called a cult group, but they are a religious group where no specific human being is venerated and no human beings worshipped like in other religious Christian groups which are not called cults, like the Catholic Church where people pray to 'saints' and worship in front of statues.