Memorial Day is a day designated for honoring and remembering those who died for this country in war.  It was founded to honor the dead in the American civil war.  First it was observed by the placing of flowers on the graves of the dead.  Also, placing flags at the graves of each fallen veteran, and at the tombs of the unknown at Arlington Cemetery. 

In Psalms David addressed God's part in wars.  Psalms 33:13-19 The lord looks from heaven; he sees all the sons of men from the place of his dwelling he looks on all the inhabitants of the earth he fashioned their hearts individually he considers all their works no king is saved by the multitude of his army; a mighty man is not delivered by great strength A horse is a vain hope for safety neither shall it deliver any by its great strength Behold the eye of the Lord is on those who fear him on those who hope in his mercy to deliver their souls from death and to keep them alive in famine.

• Proverbs 4:7 (Amplified) says "The beginning of Wisdom is: get Wisdom (skillful and Godly wisdom)! [For skillful and godly Wisdom is the principal thing.] And with all you have gotten, get understanding (discernment, comprehension, and interpretation).