John 3:12

¹⁰ “You are Israel’s teacher,” said Jesus, “and you do not understand these things?

¹¹ Truly, truly, I tell you, we speak of what we know, and we testify to what we have seen, and yet you people do not accept our testimony.

If I have told you about earthly things and you do not believe, how will you believe if I tell you about heavenly things?

¹³ No one has ascended into heaven except the One who descended 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,

Do read the surrounding verses too, because the context often says more than a single verse.

Compare

BSB: If I have told you about earthly things and you do not believe, how will you believe if I tell you about heavenly things?
KJV: If I have told you earthly things, and ye believe not, how shall ye believe, if I tell you of heavenly things?
WEB: If I told you earthly things and you don’t believe, how will you believe if I tell you heavenly things?
ASV: If I told you earthly things and ye believe not, how shall ye believe if I tell you heavenly things?
DARBY: If I have said the earthly things to you, and ye believe not, how, if I say the heavenly things to you, will ye believe?
BLB: If I spoke to you⁺ earthly things and you⁺ do not believe, how will you⁺ believe if I should speak to you⁺ heavenly things?

ÅB: Når jeg har sagt dere de jordiske ting, og dere ikke tror, hvordan skal dere da tro om jeg sier dere de himmelske?
OTB: Hvis jeg har talt til dere om jordiske ting og dere ikke tror, hvordan skal dere da tro når jeg taler om himmelske ting?
B1930: Når jeg har sagt eder de jordiske ting, og I ikke tror, hvorledes skal I da tro om jeg sier eder de himmelske?

1 Corinthians 3:1–2
Brothers, I could not address you as spiritual, but as worldly—as infants in Christ.
Read in context
1 Corinthians 2:7–9
No, we speak of the mysterious and hidden wisdom of God, which He destined for our glory before time began.
Read in context
Hebrews 5:11
We have much to say about this, but it is hard to explain, because you are dull of hearing.
Read in context
John 3:31–36
The One who comes from above is above all. The one who is from the earth belongs to the earth and speaks as one from the earth. The One who comes from heaven is above all.
Read in context
1 Peter 2:1–3
Rid yourselves, therefore, of all malice, deceit, hypocrisy, envy, and slander.
Read in context
John 1:1–14
In the beginning was the Word, and the Word was with God, and the Word was God.
Read in context
John 3:13–17
No one has ascended into heaven except the One who descended from heaven—the Son of Man.
Read in context
John 3:8
The wind blows where it wishes. You hear its sound, but you do not know where it comes from or where it is going. So it is with everyone born of the Spirit.”
Read in context