David is gigantic in terms of his impact on the praise of the holy Name of the Lord, but we need to start from when he was called by God to serve. 1 Samuel 16:1-13 tells how the Lord chose David from among Jesse’s eight sons. He said, “Invite Jesse to the sacrifice, and I Myself will tell you what to do; you are to anoint for Me the one I point out to you.” Samuel met Eliab and thought he would be the LORD’s choice but the LORD said, “Do not judge from his appearance or from his lofty stature, because I have rejected him. Not as man sees does God see, because man sees the appearance but the LORD looks into the heart.” After rejecting several more of Jesse’s sons, Samuel asked Jesse, “Are these all the sons you have?” Jesse replied, “There is still the youngest, who is tending the sheep.” …Jesse sent and had the young man brought to them. He was ruddy, a youth handsome to behold and making a splendid appearance. The LORD said, “There–anoint him, for this is he!” Then Samuel, with the horn of oil in hand, anointed him in the midst of his brothers; and from that day on, the spirit of the LORD rushed upon David.
The battle of David and Goliath shows how unlikely David would be in conquering the giant Philistine were it not for the help of the Lord by invoking His holy and powerful Name. David had pure faith in the Lord’s protection and was able to answer the taunts of the giant as he said, “You come against me with sword, spear, and scimitar, but I come against you in the Name of the LORD of Hosts, the God of the armies of Israel that you have insulted. …David put his hand into the bag and took out a stone, hurled it with the sling, and struck the Philistine on the forehead. The stone embedded itself in his brow, and he fell prostrate on the ground. When they saw that their hero was dead, the Philistines took to flight. The Philistines retreated and David was a hero, but David still had many more battles to fight.
Following this wondrous victory, the primary battle David had to fight was to preserve his life from King Saul’s jealousy. However, the Spirit of the LORD was upon David and so almost everyone except King Saul and the pagan peoples liked David and wanted to be friends with him. David became friends with the son of Saul, Jonathan. Jonathan confided to David the schemes of his father to kill David. At one point David had to leave and live as a refugee. We read in 1 Samuel 20:42 At length Jonathan said to David, “Go in peace, in keeping with what we two have sworn by the Name of the LORD. ‘The LORD shall be between you and me, and between your posterity and mine forever.'” After this exile, Saul died and David became the King of Israel.