Disfellowshipping as practiced by Jehovah's Witnesses is not "scriptural". They have built a policy on top of a few disparate Bible verses and claim the practice is Biblical. In the Bible you do not see judicial hearings - what you do see is an example where an individual, Paul, unilaterally expels a man from the Corinthian congregation against the wishes of a congregation without a JW-style judicial process. (And if we are talking about the same man in 2 Cor, Paul quickly retracts from his position and tells them to accept the man back.) In the Bible you don't see investigation meetings, written appeals, private reproof, reinstatement requiring meeting attendance for a set period of time, restrictions on commenting at meetings, and other practices of Jehovah's Witnesses. The Witnesses list of disfellowshipping offenses is not mirrored in the Bible and is cobbled together from a variety of texts, however some, such as smoking, have a tedious Biblical basis, if at all. In the books of Acts the prohibition is given against blood and fornication. As a Witness if you commit fornication you will go through the judicial process which can lead to disfellowshipping, on the other hand freely accepting a blood transfusion will get you disassociated by actions. The Bible does not allow that some offenses can get you disassociated by actions, a legal term completely invented by the Witnesses.