The believers neglected the Greek-speaking widows.

Acts 6:1

6 During that time, many more people were becoming believers. Some of them were from other countries and spoke only the Greek language, but most of them had always lived in Israel and spoke the Hebrew language. Those who spoke Greek began to complain about those who spoke Hebrew. They were saying. “When you Hebrew-speaking believers distribute food or money to widows every day, you are not giving fair amounts to the widows who speak Greek!”