"My flesh and my heart fail, but God is the strength of my heart and my portion forever."
The Psalmist mentions the fact that sometime he can't handle all the stress of life. In his own strength, he cannot make it. He says, "My flesh and my heart fail". He is talking about the natural endurance of man, which although considerable at times, CANNOT make unaided it through every kind of crisis the world dishes up.
The good news is that the man who walks with God and depends on God is not limited to his own natural strength, nor is his reward in life something merely temporal – that is pertaining to this life only. The reward of a child of God is GOD HIMSELF. In this way, God is our PORTION.
Do you ever ask "What's in it for me?"
The answer for the Christian is: GOD.
GOD is what we get.
We get to enjoy God.
And through our trials and difficulties, God Himself becomes the strength of our lives. God is the strength of our hearts. We are not limited to natural strength.
Nor is our motivation dependent on gathering a few goodies and luxuries here on earth, or even having sexual fulfilment or a loving family. We may enjoy some of these things, but our real PORTION, our real REWARD, is to know GOD and experience Him in closeness. That is what we need to go for.
So once we see that, we won't be so bothered by the apparent success of some wicked people, who flaunt God's laws and live to serve their own wicked lusts. Concerning them the Psalmist writes:
"Surely You set them in slippery places; You cast them down to destruction. Oh, how they are brought to desolation, in a momemnt. They are utterly consumed with terrors."
Would you really want to trade places with the ungodly in the light of this?
Remember and confess with your mouth that God is the strength of your heart and your portion forever. Think about what that means. If you are going through trials and pain right now, say it:
"God is the strength of my heart and my portion forever."
Say it to yourself again and again until the power of this touches your heart!