God's Word tells us that we must always guard our hearts because it is from our hearts that the springs of life flow (Proverbs 4:23). If we allow things like arrogance, pride, and self-reliance to take root in our lives, our hearts can become hardened. If our hearts are hard, we become unable to respond to God in the way we should. When this happens, we need a heart transplant. We need to allow God to do open heart surgery, to remove our hearts of stone and replace them with hearts of flesh (Ezekiel 36:26). Our new hearts must belong to Him. They must follow after Him and treasure Him (Matthew 6:21).
It is important to keep our hearts healthy. For our physical hearts, that means eating right, feeding our bodies with healthy foods. It means being disciplined to exercise our bodies. It means staying away from doing things that can damage our hearts, like smoking. We need to take care of our spiritual hearts as well. We need to feed our minds and our souls with healthy food - the Word of God. We need to be disciplined in spiritual exercises such as worship, prayer, and Bible study. And, we need to avoid the ways of the flesh, the things that lead us into sin and away from God.
When we make sure that our hearts are healthy, we may never need a spiritual heart transplant. But, if we ever do, we can rest in the assurance that we serve a God who loves us and is always ready to remove our hearts of stone and replace them with hearts of flesh.