Contemporary English Version
If you don't believe when I talk to you about things on earth, how can you possibly believe if I talk to you about things in heaven?

Douay-Rheims Bible
If I have spoken to you earthly things, and you believe not: how will you believe, if I shall speak to you heavenly things?

If I have spoken to you earthly things, and you believe not: how will you believe, if I shall speak to you heavenly things?

earthly.

John 3:3,5,8 Jesus answered and said to him: Amen, amen, I say to thee, unless a man be born again, he cannot see the kingdom of God. . . .

1 Corinthians 3:1,2 And I, brethren, could not speak to you as unto spiritual, but as unto carnal. As unto little ones in Christ. . . .

Hebrews 5:11 Of whom we have much to say and hard to be intelligibly uttered: because you are become weak to hear.

1 Peter 2:1-3 Wherefore laying away all malice and all guile and dissimulations and envies and all detractions, . . .

heavenly.

John 3:13-17,31-36 And no man hath ascended into heaven, but he that descended from heaven, the Son of man who is in heaven. . . .

John 1:1-14 In the beginning was the Word: and the Word was with God: and the Word was God. . . .

1 Corinthians 2:7-9 But we speak the wisdom of God in a mystery, a wisdom which is hidden, which God ordained before the world, unto our glory: . . .

1 Timothy 3:16 And evidently great is the mystery of godliness, which was manifested in the flesh, was justified in the spirit, appeared unto angels, hath been preached unto the Gentiles, is believed in the world, is taken up in glory.

1 John 4:10 In this is charity: not as though we had loved God, but because he hath first loved us, and sent his Son to be a propitiation for our sins.