As I keep saying, I know very little about Oneness teaching. So I have no idea how different their understanding of the Lord Jesus Christ is.Your understanding of the Lord Jesus is different from theirs.
They also have a different understanding of who the Lord Jesus is.
Can we really say that people with different views about the nature of God can both be right?
Isn't God the One who teaches the truth?
Would He teach different and conflicting views about Himself?
If God is the source of truth, why would He lead people to hold contradictory beliefs about His own nature?
Can people who teach different doctrines truly be considered born again and to have the same faith?
I believe that God is a God of truth, and that it is by carefully studying His word, the Bible, that we find the truths about His nature. If somebody has views about God's nature that go against what we find in the Bible, for example, if somebody says that God is not eternal, or that He tells lies, then we must say, on the basis of God's word, that those views are wrong.
Because none of us has perfect understanding of the Bible, there are different ideas/teachings about matters such as baptism, Creation, and church order. Such different views don't mean that people holding them are not born again. But if somebody believes that they can be saved, not by the finished work of Jesus Christ, but by trying their best to live a good life, or because they come from a Christian family, or something like that, then they are not born again. Over and over again, the Bible says that it is by believing on the Lord Jesus Christ that a sinner is saved. For example:
(Joh 3:14-16 NKJV) And as Moses lifted up the serpent in the wilderness, even so must the Son of Man be lifted up, that whoever believes in Him should not perish but have eternal life. For God so loved the world that He gave His only begotten Son, that whoever believes in Him should not perish but have everlasting life.
(Act 16:30-31 NKJV) And he brought them out and said, "Sirs, what must I do to be saved?" So they said, "Believe on the Lord Jesus Christ, and you will be saved, you and your household."