Negatively, it is the refusal to be identified with any teacher, church, denomination, or other religious organization that does not hold to and contend for those fundamentals of the Faith concerning the Bible, Christ, and salvation. Separation is not optional but absolutely necessary when circumstances demand it. Christians must observe this separation in obedience to the Word of God. The Bible contains many Old Testament examples as well as New Testament warnings and commands concerning separation, which the Christian cannot ignore without being disobedient to God and His revealed Word. It is important to keep in mind that these categories often overlap and cannot always be strictly compartmentalized.
False teaching occurs both in the church and in the world.
Sinful practices of the unsaved sometimes enter the church. In separation, as in other aspects of Christian living, the Christian must act according to the principle of love. The believer who really loves the purity of the church will not sacrifice that purity for the sake of ecumenism. A true love for the brethren does not encourage sin through the tolerance of evil practices. Although what follows is an attempt to be clear and specific, it is impossible to lay down hard and fast rules to prescribe the proper course of action for every situation which may arise in the life and ministry of the Christian.