How do we know the importance of separation from the world in Christianity?

Scripture emphasizes the necessity of separation from worldly values and behaviors for those who claim to follow Christ. In 2 Corinthians 6:17, Paul urges believers to come out from among them and be separate, which suggests an intentional distancing from the undertones of the secular world. This separation is not merely physical but also spiritual, as Christians are called to manifest a unique identity that reflects the character and holiness of God. The scriptural foundation for this separation is rooted in the understanding that friendship with the world equates to enmity with God, highlighting the stark contrast between the values of Christ's kingdom and those of the world.