Your cry of weariness is not unknown to the Lord, for human strength in any form will spend itself in due time, and all strength apart from God is derived strength and must come to an end. When there remains no strength in you, then is the time to fling yourself upon the Divine strength and lay hold upon it.
The promise stands, He gives power to the faint and to them that have no might He increases strength. They that wait upon the Lord shall renew their strength. This renewing is not by your own resolve, but by waiting upon Him. Therefore stop a moment and breathe a prayer for more strength, for if the duty before you is beyond you, there is strength laid up for you somewhere, and that somewhere is in Christ alone.
And with that strength He gives peace, a peace that is a blessing and brings no sorrow with it. You will keep him in perfect peace, whose mind is stayed on You, because he trusts in You. This is not the false peace of a conscience lulled to sleep, but peace through the blood which has made a full atonement. The blood of Jesus whispers peace within, and even with sorrows surging round and thronging duties pressed, to do the will of Jesus is rest. Bear your sorrow with Him, and keep your mind stayed upon Him, and He will keep you in peace, peace.
And for this night, remember that so He gives His beloved sleep. Sleep is a gift of His love, a sleep of contentment and security for those whose conscience is right with God. It is a means of refreshment by the recruiting of our exhausted strength to fit us for fresh exercise when we awake. As you lie down, you may say, with the world, myself and Thee, I, ere I sleep, at peace shall be.
Let us pray together for you.
O Father, look upon this weary one who is physically and emotionally exhausted. Surround this child with Your presence, and let Your perfect peace guard heart and mind through Christ Jesus. Forgive all sin through the blood of the Lamb and whisper peace within. Grant this night peaceful, restorative sleep, for so You give Your beloved sleep, and renew strength for tomorrow. Increase strength where there is no might, and let Your joy be the glory of our strength, that tomorrow may be lived in Your power and to Your praise. In the name of Jesus Christ our Lord, Amen.