As sojourners and pilgrims (ως παροικους κα παρεπιδημους). This combination from the LXX (Genesis 33:4; Psalm 39:13). See 1. Peter 1:1 for παρεπιδημος and 1. Peter 1:17 for παροικια and Ephesians 2:19 for παροικος (only there and here in N.T., Christians whose fatherland is heaven).

To abstain from (απεχεσθα). Present middle (direct) infinitive of απεχω, old verb, to hold back from (1. Thessalonians 4:3). In indirect command (to keep on abstaining from) after παρακαλω (I beseech). With the ablative case των σαρκικων επιθυμιων, the grosser sins of the flesh (for σαρκικος see 1. Corinthians 3:3) like the list in 1. Peter 4:3.

Which (αιτινες). "Which very ones." Like Latin quippe qui.

War against the soul (στρατευοντα κατα της ψυχης). Present middle indicative of στρατευω, to carry on a campaign (James 4:1). See this struggle between the flesh and the spirit vividly pictured by Paul in Galatians 5:16-24.