1 Samuel 17-18,  Psalm 102,  Mark 12:1-12,  2 Corinthians 7

1 Samuel 17-18:

One of the most famous stories in the Bible—David and Goliath—is about to ensue (1 Samuel 17). The basics of the narrative are familiar enough to many: a young sheep boy stands up against the enemy of God’s people, a giant of a man called Goliath, and defeats him. What is sometimes less well understood is the intended lesson. In fact, though, the narrator makes the point of the story crystal clear himself through the words of David: 

…that all the earth may know that there is a God in Israel, and that all this assembly may know that the Lord saves not with sword and spear. For the battle is the Lord’s, and he will give you into our hand. (17:46-47) 

The purpose of David’s amazing victory is not to teach us that there is a particular technique which could cause us to defeat the giants in our lives. The purpose is to teach us that, despite the huge tactical and physical disadvantage which David labored under, God caused David to win because David trusted God. This victory was by God’s hand alone (“the battle is the LORD’s,” 17:47). It has an evangelistic purpose (“that all the earth may know that there is a God in Israel,” 17:46), as a well as a discipleship purpose (“that all this assembly may know that the LORD saves not with sword or spear,” 17:47). In other words, David and Goliath is not a story about how to kill giants. It is a story about how God and God alone saves, and this gives God glory among all nations and among his own people, too. David, to be sure, in this story is a type of Christ who rescues us against our enemies. We are to trust in Christ, trust in God, and not think that what matters in our lives is whether we have found the right technique or not. 

David and Jonathan become fast friends (18:1). In fact, they make a covenant whereby Jonathan ceremonially hands over to David the seals of his office (18:3-4). Jonathan is saying that after his dad Saul, it is not he who will be king, but David. 

God is with David (18:12, 14), and Saul becomes jealous (18:6-9, 12-15). He fears that David’s popularity will undermine his own authority, and so he comes up with various ruses to get David killed by the Philistines (18:17-29). But instead of this achieving its desired end, all it does is make David even more popular as the battles merely give David opportunity after opportunity to win (18:30). One time he even tried personally to kill David (18:10-11). God is able to turn the schemes against us from other people for our own good. They plan it for evil, perhaps, but God plans it for good (Gen. 50:20). 

Be faithful, trust in God and in his Christ, and God will win the victory.