There are many different cliche sayings about the mind and how it connects to your life as a whole. One is 'A mind is a terrible thing to waste', another is 'The idle mind is the devil's workshop.' The list goes on and on. Lets look at the biblical references of how the mind is connected to life.
Romans 12:2 Do not be conformed to this world, but be transformed by the renewal of your mind, that by testing you may discern what is the will of God, what is good and acceptable and perfect.
Translation: Ever been in an unfavorable life situation and nothing changed until you changed your thought process? Well that is what Romans 12v3 is saying. If you want better, then you must think then do better!
Philippians 4:8 Finally, brothers, whatever is true, whatever is honorable, whatever is just, whatever is pure, whatever is lovely, whatever is commendable, if there is any excellence, if there is anything worthy of praise, think about these things.
Translation: Figure out what is truly of importance to self success. Many of the things that are truly important are just a waste of time, mentally, physically and spiritually.
James 1:8 He is a double-minded man, unstable in all his
Translation: Make up your mind. Nothing can be accomplished by pushing and pulling in two different directions.
Isaiah 26:3 You keep him in perfect peace whose mind is stayed on you, because he trusts in you.
Translation: Since God is all knowing, all present, all powerful and more, why wouldn't you keep your mind, body and spirit focused on Him? He can definitely keep us in perfect peace serving a God that IS Everything!