Any pattern of life associated with our past is categorized as worldly whiles that which is associated with our new life in Christ is categorized as Christian.
Thus there are worldly fashion, worldly music, and worldly relationships. Anything in our world that is not centered on God and communicates godly values is worldly and leads to death.
As peculiar people God does not want us to conform to the standards of the world but be transformed by the renewing of our minds Romans 12:1-2
Our bodies have become the temple of the Holy Spirit and as such we cannot yoke together with unbelievers and unbelievers’ lifestyle 2 Cor 7:14-18.
If we do we crucify the son of God afresh and put Him to an open shame Heb 6:4-6