No it's definitely spiritual. It can be heard, but not understood. How else do those who learn of the father come to Christ? They are led spiritually until their eyes are opened to the truth of the gospel
No, they come to Christ only by the Father giving them to Christ, and Christ to them. Of themselves they cannot do so. God opens the eyes; man cannot do so on his own - they must be opened for them, but He does so only for His elect, not everyone.
[Jhn 17:2 KJV] 2 As thou hast given him power over all flesh, that he should give eternal life to as many as thou hast given him.