Why do catholics believe this about Pentecostals?

The oneness Pentecostals baptize in the name of Jesus. because they don't baptize in the name of the father and of the son and of the holy spirit the catholics say their not christians. the apostles baptized in jesus name. God sent an angel to Cornelius Acts ch. 10 the angel said to Cornelius that Peter will tell you what you need to do. But anyways Peter baptized people in the name of the Lord Jesus Christ.I read about the catholic church and I read about what they thought about other denominations and they think the oneness are not christian which the bible says God knows who are his elect. The catholic church don't know who are God's elect; only God does.