"Now we command you, brethren, in the name of our Lord Jesus Christ, that ye withdraw yourselves from every brother that walketh disorderly, and not after the tradition which he received of us." (2nd Thessalonians 3:6)

Even in the earliest letters of Paul, we see that church discipline is an important part of the activities of the Lord's Church.

This is not an excommunication. The church has not the wisdom nor authority to decide who is going to heaven or hell. Paul is instructing the church to withdraw fellowship to bring about repentance.

The one who goes astray is still called a brother.

Paul continues this reasoning in verses 13-15.

"But ye, brethren, be not weary in well doing. And if any man obey not our word by this epistle, note that man, and have no company with him, that he may be ashamed. Yet count him not as an enemy, but admonish him as a brother." (2nd Thessalonians 3:13-15)

To be a member of a church, we have promised to do our best to walk like Jesus Christ. When we do not, we should receive some form of discipline. This might be that we cannot take communion or it may be that we have fellowship withdrawn altogether.

The born again child of God needs fellowship like His Creator. If done properly, this withdrawal of fellowship will bring about repentance because the erring brother misses and hungers for the fellowship of the saints.

Also note, it does no good to exclude someone from communion and then spend large amounts of time with them outside of church like nothing is wrong. This is not a withdrawal of fellowship. Contact should be made only to reinforce the need for repentance and returning to the church.