The realization that the body and the heart will fail is sobering. It puts a new perspective on how one thinks of life itself. The flesh is the body and the strength is built up in the person from the younger days. It peaks and will decline in the latter years of life. The obvious example is of the activities of a young aged. The body does not function at the same level in young and the aged. The loss of strength is made obvious when the support of a cane is needed even for walking. This body will die eventually.
The failure of the heart is caused it by a combination of factors. Looking at a bleak future the heart can fail. Fear can cause the heart to fail. Taking a tremendous loss can cause ones heart to fail. The result is people become depressed. There is no joy. The psalmist is not alarmed or disheartened by the failure of the flesh and the heart because he has found someone who can take care of these. He found a cure for his loss of strength and failing heart in God. No matter what it is, God is able to take care of it.
God is the one who created us and gave us life. Gen. 1:27-28; Gen.2:7. The psalmist realized that it is only God who can strengthen the heart. He is the only one who can make the heart truly rejoice. He put his trust in Him. Psa. 18:2. The failing flesh finds new hope in Christ because of the new body he will receive. Death is replaced by life with no pain, suffering, anxiety or tears. In the twinkling of an eye we shall all be changed. It is with this body and joy in out heart we will enjoy eternity. Forever with the Lord. It is up to us to surrender ourselves to God. Hang our hopes on Him. Our Lord will be our constant companion even through eternity. Have confidence in God. Believe on Him. Let Him take charge of you. AMEN DJ