When someone has heart problems... a doctor will usually provide a specific regimen for them to follow. It can include a specific diet, exercise and a manner of living, that is intended to preserve or restore their hearts to better health.
However, it is up to the patient to follow that program dutifully... if they expect to see any improvements with their physical health. They must be diligent in making heart healthy decisions. It isn't always an easy task but if someone wants to live... they will make those changes.
The same is true with our spiritual hearts... we must faithfully keep our feelings out of the "facts"... that keep us in line with the Word of God. We must make it a point to declare the Word of God in our lives everyday. We must keep our thoughts on those things which are true, honest and just. We must think on what is pure, lovely and of a good report. (See: Philippians 4:8) In doing so we can be sure we are walking in the spirit and not our own flesh. As our relationship with Jesus lines up with the Word of God... we will begin to know him more fully and intimately.