So I say this, and affirm in the Lord, that you are to no longer walk just as the Gentiles also walk, in the futility of their minds Ephesians 4:17, NASB
As followers of Jesus Christ, we are no longer to walk (live our life) in sin the way we did before our transformation by the indwelling of the Holy Spirit. Christians must mirror Jesus, not the world which has no restraint. For the world is driven by the lust of the flesh to do things that are detestable to the Lord.
The lives of the unbelievers are lived in vain, but the lives of believers are lived with a purpose that will have an eternal reward.