That is not true at all. Do some research and you will find out that Israel has been killing innocent Palestinians for over 75 years.
Have you ever heard of the Nakba? It was a day when Israel absolutely massacred the Palestinian people and unrightfully kicked them out of their houses. Guess when that was? 1940. So no, everything wasn't peaceful right before October 7th. Israel has been killing Palestinians, kicking them out of their homes, putting them in prisons for no reason, etc. for years.