This is an important metaphor in Scripture. The church has many different parts. Each part has different functions. They combine to make one church. All of the different parts are necessary. Each part is to be concerned for all the other parts, even those that seem less important. (See: [[rc://en/ta/man/jit/figs-metaphor]])
In reading the Old Testament, the Jews would have substituted the word "Lord" for the word "Yahweh." This sentence probably means that no one can say that Jesus is Yahweh, God in the flesh, without the Holy Spirit's influence drawing them to accept this truth. If this statement is translated poorly, it can have unintended theological consequences.