Definition and Context:
A Call to Separation in biblical terms refers to the divine directive for God's people to distinguish themselves from sin, idolatry, and the practices of the surrounding nations. This concept is rooted in the idea of holiness, where God's people are set apart for His purposes. The call to separation is both a physical and spiritual mandate, emphasizing purity, devotion, and obedience to God.

Old Testament Foundations:
The concept of separation is deeply embedded in the Old Testament. In Leviticus 20:26, God commands the Israelites, "You are to be holy to Me because I, the LORD, am holy, and I have set you apart from the nations to be My own." This call to holiness and separation is reiterated throughout the Mosaic Law, where the Israelites are instructed to avoid the customs and religious practices of the Canaanites and other neighboring peoples (Deuteronomy 7:1-6).

The account of Abraham is an early example of separation, as God calls him to leave his country and family to go to a land that He would show him (Genesis 12:1). This physical separation symbolizes a deeper spiritual journey of faith and obedience.

Prophetic Emphasis:
The prophets frequently called Israel back to a life of separation from idolatry and sin. In Isaiah 52:11, the prophet exhorts, "Depart, depart, go out from there! Touch no unclean thing! Come out from it, purify yourselves, you who carry the vessels of the LORD." This call underscores the need for purity and dedication to God, especially in times of national apostasy.

New Testament Application:
In the New Testament, the call to separation takes on a more spiritual dimension. Believers are called to separate themselves from the sinful practices of the world while living in it. In 2 Corinthians 6:17, Paul writes, "Therefore come out from among them and be separate, says the Lord. Touch no unclean thing, and I will receive you." This passage highlights the importance of moral and spiritual purity for Christians.

The apostle Peter echoes this sentiment in 1 Peter 1:15-16, urging believers to be holy in all their conduct, as God is holy. The call to separation is not about physical withdrawal from the world but about living a life that reflects God's holiness and righteousness.

Practical Implications:
A Call to Separation involves both individual and communal aspects. Individually, believers are to abstain from sinful behaviors and influences that can lead them away from God. This includes avoiding partnerships or relationships that compromise their faith (1 Corinthians 15:33).

Communally, the church is called to maintain doctrinal purity and moral integrity. This involves church discipline and the upholding of biblical standards within the community of believers (1 Corinthians 5:9-13).

Conclusion:
The biblical call to separation is a timeless principle that underscores the distinctiveness of God's people. It is a call to live in the world but not be of the world, maintaining a life of holiness and devotion to God.