Discipline can take many forms. One is to exclude from the congregation a person who no longer wants to live by God's standards, or who refuses to do so. A person who is disciplined may repent and turn around. In the process, the congregation are also disciplined in that they learn the importance of conforming to God's high standards as outlined in scripture.
"No discipline seems for the present to be joyous, but grievous; yet afterward to those who have been trained by it yields peaceable fruit, namely, righteousness." (Hebrews 12:11)
Does this mean that if a Christian brother or sister stumbles into sin they are automatically expelled?
Disfellowshipping someone should be used only after all other attempts of reasoning with the person in order bring them back into the truth have failed, then the congregation is justified in expelling them from their midst.
"But foolish and unlearned questions avoid, knowing that they do gender strifes. And the servant of the Lord must not strive (act in strife); but be gentle unto all men, apt to teach, patient, in meekness instructing those that oppose themselves; if God peradventure will give them repentance to the acknowledging of the truth; And that they may recover themselves out of the snare of the devil, who are taken captive by him at his will."
Paul told the congregation:
"I wrote unto you in an epistle not to company with fornicators: Yet not altogether with the fornicators of this world, or with the covetous, or extortioners, or with idolaters; for then must ye needs go out of the world. But now I have written unto you not to keep company, if any man that is called a brother be a fornicator, or covetous, or an idolater, or a railer, or a drunkard, or an extortioner; with such an one no not to eat. For what have I to do to judge them also that are without? do not ye judge them that are within? But them that are without God judgeth. Therefore put away from among yourselves that wicked person." (1 Corinthians 5:9-13)
Disfellowshipping is a demonstration of love for the wrong doer, it encourages them to repent.
Disfellowshipping someone because they do not believe the same way would be wrong, it is for those that are sinning, breaking God's law based on real scripture!
Everyone understands according to their own spiritual growth. Instead it is to be used for those that are in a clear state of sin according to Gods word (example: fornication, covetous, breaking the ten commandments), and not the organizations view of sin (example: wearing jewelry, dancing), but then again, would it make any sense to fellowship with this type of organization anyway?
The Church of God Proclaimed