Recently when I was reading the words of Jesus in the Gospel of Matthew, I was struck by these simple yet profound comments about the human heart.

But what comes out of the mouth proceeds from the heart, and this defiles a person.  For out of the heart come evil thoughts, murder, adultery, sexual immorality, theft, false witness, slander. These are what defile a person. (Matthew 15:19-20)

Make a tree good and its fruit will be good, or make a tree bad and its fruit will be bad.  For a tree is known by its fruit.  (Matthew 12:33)

In Hebrew language and culture, the word heart refers to far more than just your feelings. It also refers to your will, your mind, your thoughts, your motivations – everything that is at the core of your being and makes you who you are.  It’s worth noting that when Jesus listed things that come out of the heart and have the power to make us unclean, the first item on his list was evil thoughts.  Thoughts give rise to actions.  As a man thinks in his heart, so is he.  As a woman thinks in her heart, so is she. (Prov. 23:7)

But lest we become discouraged, let’s also note that Jesus said it is possible to make the tree good, and then its fruit will be good.  When he said this, he was talking about our hearts.  The tree is an analogy for the human heart, and the fruit is an analogy for our words and actions – the things that flow from our lives and affect others.  Jesus is saying that training yourself to behave better isn’t enough.  It is the heart that needs to be transformed.

So how do we go about this? How do we train our hearts?

No doubt someone will want to remind me that only Jesus can create a new heart in any of us.  I completely agree that it’s impossible for us to convert our hearts by our own efforts.  Only the blood of Jesus and the waters of baptism have the power to cleanse our guilty consciences, put our old identity to death and make new creatures of us.  Still, I found that even after I had surrendered control of my life to Jesus, and received His offer of forgiveness and new life, the transformation of my thought life and my emotional life was not instantaneous or automatic.  I knew that I was accepted and forgiven, and I desired to produce fruit that was pleasing to God, but I still had to engage in a process of renewing or retraining my mind and heart.  I know I’m not alone in this.  Mark Virkler, who has studied this area for years, has estimated that up to 80-90% of the thought life of the average evangelical Christian is negative.   Sometimes it can seem like a constant battle to bring our unruly thoughts and emotions into alignment with the will of God as we see it embodied in Jesus.

I’d like to suggest that sometimes one of our biggest problems is that we try too hard.  In this battle to retrain our hearts and minds, the victory belongs to the Lord – and He has already won that victory on the cross.  In light of this powerful and liberating truth, I have found that one of the most effective weapons at my disposal is the simple decision to stop trying to change myself, and just begin to give thanks.

James (3:6) says that the tongue has power to influence the whole course of our lives. Although evil thoughts, evil words  and evil actions arise from polluted hearts, the reverse is also true. Good words – specifically, words of thanksgiving – have the power to cleanse and renew our minds and hearts, change our thinking, create faith in us (remember, faith comes by hearing) and cause genuine gratitude to well up within us until we begin to think like grateful people. And once our hearts begin to be ruled by gratitude instead of complaints, worries, guilt and self-pity, we are on the road to victory.

Did you know that in the Greek language (in which the New Testament was written) the word for giving thanks is related to the word for grace?  No doubt that’s why the practice of praying before meals is sometimes referred to as “saying grace”.  This link between thanksgiving and grace reflects something that all disciples of Jesus have experienced.  If you want to have a constant experience of the overflowing grace of God in your life, give thanks !

I’ve heard many people say that it is hypocritical and insincere to say things you don’t mean or don’t feel.  Of course I agree that if your words of gratitude are a total sham, an outright lie, then you are just deceiving yourself and others.  But what if you recognize that you ought to be thankful, even though at the moment you don’t feel very thankful, and so you choose to give thanks to God (or to the people around you) because you know it is the right thing to do?  The wonderful truth about the way God has made us is that if we train our tongues to express gratitude, we are actually changing the way we think.  Before long we begin to see all kinds of reasons to praise God, and the whole atmosphere of our life becomes more positive.

The other day, during our weekly Skype conversation with our son Simeon, Marion and I watched him training his little girl Sophie to say “Thank you”.  Most parents want their children to be polite.  Yet somehow, as adults in our culture we seem to have forgotten the habit of giving thanks.  Maybe this is a habit we need to re-learn. Hearts that have been trained to be thankful to God for His amazing goodness will experience His power and love in rich measure, and will also naturally overflow in gratitude to the people around us.

When Simeon was a little boy, on his third birthday Marion and I gave him a new housecoat.  He was so pleased with that housecoat, he was thanking us for it for days afterwards.  We were on a tight budget at the time, and I was touched at his simple but heartfelt expression of gratitude.  And of course, my heart was wide open to him as a result. My joy at hearing my child thank me is a reflection of the father heart of God.  He is always willing to bless His children, but if our hearts are cold and hard, we will be distant from Him and unable to receive most of what He longs to give us.  Did you know that when you thank God, you are also blessing Him and bringing Him joy? Not only does thanksgiving have power to transform our hearts, it also touches the heart of God, and has power to bring us near to Him so that we can easily receive His blessings.

Create in me a clean heart, O God,
and renew a right spirit in me.  (Psalm 51:10)