Some argue that the Bible is contradictory concerning who killed Saul. The argument is that 1 Samuel 31:4 says that Saul killed himself, but 2 Samuel 1:8-10 says that the Amalekite killed Saul. However, there is a very reasonable explanation that solves this alleged contradiction in the Bible.
Saul said to his armor-bearer, “Draw your sword, and thrust me through with it, lest these uncircumcised come and thrust me through, and mistreat me.” But his armor-bearer would not, for he feared greatly. Therefore Saul took his own sword and fell upon it.1 Samuel 31:4
8 And he said to me, ‘Who are you?’ I answered him, ‘I am an Amalekite.’ 9 And he said to me, ‘Stand beside me and kill me, for anguish has seized me, and yet my life still lingers.’ 10 So I stood beside him and killed him, because I was sure that he could not live after he had fallen. And I took the crown that was on his head and the armlet that was on his arm, and I have brought them here to my lord.”2 Samuel 1:8-10
1 Samuel 31:4 records what actually happened, while 2 Samuel 1:8-10 records the Amalekite’s account of what happened. The most probable explanation is that the Amalekite lied to David for personal gain. This is supported by verse 10, where the Amalekite says, “And I took the crown that was on his head and the armlet that was on his arm, and I have brought them here to my lord.” It seems the Amalekite was seeking to please David by telling him that he killed Saul and brought David gifts from what Saul was wearing.
However, the Amalekite’s plan failed, since David condemned the Amalekite’s killing of Saul and ended up having the Amalekite killed.
To read more answers to alleged and apparent contradictions in the Bible, see “Contradictions” in the Bible Answered.
These books are also excellent resources: