Even if I can’t depend on my flesh, surely my heart will never fail me. That all depends on whose hands you put your heart in; if you keep your heart in your own hands (the flesh) then you will be deceived by your own heart! If what you feel and how you think comes from the flesh then your heart is corrupted along with your flesh. God wants your heart to be strong and your life to be blessed, but you can’t make that happen.
The flesh will always be the flesh and cannot be “fixed”, thus it will one day be replaced by an immortal body that will live forever. Your heart (your soul – your mind, will and emotions), on the other hand can be renewed by the power of God living within you. By the renewing of your mind you are transformed. When you put your life into God’s hands and depend on the Lord and His Word to feed and nourish your soul every day, you grow stronger in the Lord; God becomes the strength of your heart.
If you put your trust in the flesh, your life will be an endless series of ups and downs based on people and circumstances that surround you and intersect with your life in one way or another. There is nothing to sustain you when you choose to trust in your own strength and it will eventually fail you. But, when you put your trust in the Lord, He will never fail you — He will strengthen you so that, even when you are weak in your own strength, you will be strong in His strength!
And for even more good news, this is not a blessing that you can use up or that will run out if you use it too much. It is not like you are allotted so much of God’s help and strength and then, when you run out, you are out. God is always with you and will never leave you, He is the strength of your life, therefore you can say, “The Lord is my portion forever!”