David the Great King commanded respect because he was God's "Beloved" (the English translation of his name)
After he presented himself as a servant to the Lord's backslidden anointed, David declared:
"What shall be done to the man that killeth this Philistine, and taketh away the reproach from Israel? for who is this uncircumcised Philistine, that he should defy the armies of the living God?" (1 Samuel 17:26)
David recognized that Goliath - an uncircumcised -- did not have a covenant with the Lord. David did! Right away, David knew and believed that he had nothing to fear!
When King Saul questioned whether David should go up to take down the Giant, David championed all that the Lord had done for him:
"Thy servant kept his father's sheep, and there came a lion, and a bear, and took a lamb out of the flock:
"And I went out after him, and smote him, and delivered it out of his mouth: and when he arose against me, I caught him by his beard, and smote him, and slew him.
"Thy servant slew both the lion and the bear: and this uncircumcised Philistine shall be as one of them, seeing he hath defied the armies of the living God." (1 Samuel 17: 34-36)
Now, most people have read this passage and therefore assume that it was David's persistence and prowess as a shepherd that would help him to best Goliath of Gath. But David expounds on the true reason for his confidence:
"The LORD that delivered me out of the paw of the lion, and out of the paw of the bear, he will deliver me out of the hand of this Philistine. And Saul said unto David, Go, and the LORD be with thee." (1 Samuel 17:37)
David trusted in the Lord to succeed, not his own efforts. He stood on the love that God had for him, not his own power.
Everyone of us commands respect to the extent that we grow in grace and knowledge of the Lord's love for us! When we have the stability of knowing that we are accepted as God's Beloved, a right conferred on every individuals who believes on the Lord, from Father Abraham to the present day, then all our challenges and all fears melt away.