Faith is not only essential for salvation but is necessary in all aspects of the Christian life.
Paul continues to instruct Timothy using 7 pictures or metaphors. The 5th is the workman.
Various ways heart, soul, and mind are used in the Old and New Testaments.
The word heart has several uses in the New Testament.
Paul makes a practical appeal to Timothy using 7 metaphors to help explain Timothy's responsibilities to the Lord.
We must remember our enemies and what the Lord did to Miriam.