Rodney Stark, in The Rise of Christianity: A Sociologist Reconsiders History draws a distinction between cults and sects and says that Jesus’ Kingdom movement would more accurately be called a sect—which he defines as a “...schism within a conventional religious body (in this case, Judaism) when persons desiring a more otherworldly version of the faith break away to ‘restore’ the religion to a higher level of tension with its environment.”, until the resurrection, when it became a cult—”...not simply new organizations of an old faith: they [cults] are new faiths, at least new in the society being examined.”
Furthermore, says Stark, sects appeal especially to those “if not the dispossessed, at least of the lower social standing than those who stick with the parent body”, but cults ” must draw upon the more privileged for their recruits.”-ibid
This sounds very much like the evolution of Jesus’ Kingdom of God (sect) as it became Paul’s Christianity (cult).
In any case, Christianity today is neither a sect nor a cult. It’s a full-blown religion with cults and sects of it’s own.