Question: Last night I watched the story of David. My heart was concerned and upset that during the story line, God, through the prophet Samuel told Saul to kill the Amelikites, children, women and men. Why? Especially children.
Answer: It may help to read Exodus 17 in addition to 1 Samuel 15.
In Ex 17:8-15, the Amelkites waged war on Moses and the Chosen People while they were in the desert.
Pay very close attention to how the Chosen People win the battle.
Moses stood at the top of a hill - whenever his arms were raised (think of Jesus with his hands outstretched on the cross), things went well for the Israelites.
When his hands lowered (he stopped imitating the crucified Christ), things went badly.
Ultimately, Moses sat down on a rock and had a man on each side to hold up his arms.
Now, read the Exodus passage again, using typology.
Sin (the Amelkites) wages war on the members of the Church (the Chosen People).
Through the intervention of the crucified Christ (Moses with arms outstretched, a man on each side, as Christ had a man crucified on each side of him), and the Church/Peter (the rock upon which Moses sat), sin is conquered.
God then promises to wipe out all memory of sin (the Amelkites).
For this reason, Christ made a sacrifice of Himself (Moses built an altar).
So, in 1 Sam 15, the wiping out of the Amelkites by the King of the Chosen People, Saul, is like unto the wiping out of the Egyptian army by the flood of the Red Sea. The latter destruction has always been seen as a prefigurement of baptism.
In both cases, God is trying to tell us how He will destroy sin and restore mankind.
With the Egyptians, He shows that He does this through baptism.
Here, He shows that it is accomplished through His Kingship, and our willingness to become like the crucified Christ.
Keep in mind that the deaths of the Amelkites does not mean that any of THEM necessarily go to hell.
Loss of the body is not so serious as loss of the soul.
But the wiping out of these people is a foreshadowing of the wiping out of sin, the conquering of the devil and his minions.
As Paul said in Corinthians, "these things were written down for our instruction, upon whom the end of the ages has come."