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.
Trinitarian Christians claim to be monotheists thought their subgod Jesus has lesser qualities in common than many polytheists their main god and subgods. God may perhaps not to be found in perceivable attributes but when looking around and reading the Bible like the words are written in that book then it should not be so difficult and not so confusing to come and see Who God really is.