1 Peter 2:11

11 Beloved, I urge you as aliens and strangers to abstain from fleshly lusts which wage war against the soul.

Peter here is calling them “aliens” as he did in the beginning of his letter, intending to bring into focus their citizenship in heaven and that they are not of this world. Peter wants them to know that if they are to be a holy people of God they must begin their Christian journey by abstaining from fleshly lusts, because that behavior will give them trouble in the spiritual life. In fact, it will bring them back to the darkness of their previous life and put them at war against their new life with Christ. Therefore, the Christian is to “abstain” from (or retreat from) fleshly lusts (animal desires) so that he may continue a life of Christian joy and peace and love and all that the Holy Spirit brings into the soul.