Jesus said in the Bible, "Love your neighbor as yourself".
If you really do it: love others as yourself. So,
You will be convinced that "all dharma circles are one me" Because you love others as yourself.
This is a biblical theory. Of course, it is also a Buddhist theory.
Someone asked: Why did Jesus save mankind?
Answer: Because Jesus regards human beings as his own children.
Someone asked: Why should the Buddha benefit all beings?
Answer: Because the Buddha regards all beings as the aggregation of karma.