The Gospel of John, Day 19: ch. 3, vv. 9-15

⁹ “How can this be?” Nicodemus asked.

¹⁰ “You are Israel’s teacher,” said Jesus, “and do you not understand these things? ¹¹ Very truly I tell you, we speak of what we know, and we testify to what we have seen, but still you people do not accept our testimony. ¹² I have spoken to you of earthly things and you do not believe; how then will you believe if I speak of heavenly things?

At this point in Jesus' ministry, there are already people who have been born again.  I think this is the earthly thing that Jesus is talking about.  You can see the changed lives.  You can see lives renewed into God's kingdom.  Jesus also talks about heavenly things.

¹³ No one has ever gone into heaven except the one who came from heaven—the Son of Man. ¹⁴ Just as Moses lifted up the snake in the wilderness, so the Son of Man must be lifted up,¹⁵ that everyone who believes may have eternal life in him.”

Now Jesus speaks of the heavenly things.  Only Jesus has been to heaven, he came from heaven!!  We have eternal, that is unearthly and heavenly, life if we believe in Him.