The mind grows by taking in, but the heart grows by giving out.
From 2 Corinthians 9:6-7: “The point is this: the one who sows sparingly will also reap sparingly, and the one who sows bountifully will also reap bountifully. 7 Each of you must give as you have made up your mind, not reluctantly or under compulsion, for God loves a cheerful giver.”
Outlook determines outcome and attitude determines action.
From Philippians 4:8: “Finally, beloved, whatever is true, whatever is honorable, whatever is just, whatever is pure, whatever is pleasing, whatever is commendable, if there is any excellence and if there is anything worthy of praise, think about these things.”
There is a difference between doubt and unbelief. Doubt is a matter of mind: we cannot understand what God is doing or why He is doing it. Unbelief is a matter of will: we refuse to believe God’s Word and obey what He tells us to do.
From Mark 9:24: “Immediately the father of the child cried out, ‘I believe; help my unbelief!'”