CLAIM: Critics note that the Philistine nation did not exist until the 12th century BC. This, they charge, is an anachronism on behalf of the author of Genesis.
RESPONSE: The author of Genesis does not claim that the Philistine nation was large (as it was in the 12th century or later). Instead, the Philistines were most likely a small tribe at this time. We detect this from the text in Genesis 21:25, when the Philistine king (Abimelech) is intimidated by Abraham and his tribe of a couple hundred men! Moreover, these passages only mention Gerar, which was the smallest of the Philistine city-states. The bigger city-states are not mentioned (e.g. Ashdod, Ashkelon, Ekron, Gath, and Gaza –Josh. 13:3; 1 Sam. 6:17). Kitchen notes, “We know so little about the Aegean peoples as compared with those of the rest of the Ancient Near East in the second millennium BC, that it is premature to deny outright the possible existence of Philistines in the Aegean area before 1200 BC.”
 See footnote in Kitchen, Kenneth Anderson. Ancient Orient and Old Testament. London: Tyndale, 1966. 80.