"Do not reject me in the time of my old age ... for my enemies speak against me ... saying, God has forsaken him ; Pursue it and seize it, for there is none who delivers it." Psalm 71. 9-11
"David went down, and his servants with him, and they fought with the Philistines ; And David was tired." Read 2 Samuel 21. 15-22
Is history experiencing a more dreadful humiliation than that undergone by the giant Goliath, champion of the Philistines ? He was overwhelmed by David's slingshot, a simple shepherd ! This humiliation was felt by all his people. But after a long reign punctuated by hard fights, painful trials and also some falls, David aged, he is tired. And the enemy, who never disarms, wants to take advantage of David's weakness; He attacked Israel with the intention of eliminating David : "Jishbi-Benob, who were children of the giant ... thought to strike David" (2 Sam. 21:16). God delivers David from the danger by his nephew Abishai. The enemy renews his attack with three other giants : God renews his protection and delivers David by three other warriors (2 Samuel 21).
In this context, David, who is probably the author of Psalm 71, expresses the feelings he felt in his old age. These are perhaps the same sentiments that certain weary Christians may experience today, for Satan, prefigured by Goliath and his descendants, never renounces to attack the children of God. And he is even more deceived if he discerns in them any signs of weakness, fatigue, or discouragement.
The psalmist nevertheless affirms from the beginning of this psalm that his faith is intact ; It encourages him to implore the help he has experienced from his childhood : "In you, O Lord, I have put my trust ... you are my stronghold ... you are my confidence from my youth." This proven knowledge of his Savior "is the continual subject of his praise." It is thus the happiness of a Christian of advanced age, tired and in the presence of danger, to be able to invoke his God in all circumstances and with complete confidence : "I will go in the power of the Lord." It is also the happiness of being able to proclaim his righteousness and truth "to all who will come" by affirming : "My lips, and my soul, which you have redeemed, will exult when I sing your praises" (verses 16, 22, 23).
Source (To pleasing the Lord)