The effects of sin on our bodies

Whew - this could be a long subject! I thought I'd start with Proverbs 14:29-31

A patient man has great understanding,
but a quick-tempered man displays folly.
A heart at peace gives life to the body,
but envy rots the bones. (NIV)

A sound mind makes for a robust body,
but runaway emotions corrode the bones. (The Message)

The mind, the heart... separate yet interlinked, at the core of our being. How to get a sound mind?

2 Timothy 1:7 says: For God has not given us a spirit of fear and timidity, but of power, love, and self-discipline

Somewhere - maybe in the Good News version - I have read 'self-discipline' as 'sound mind'. God has given me a sound mind - which I need to discipline. Then my body will indeed be 'robust'!