New Revised Standard Version
But Joshua said to the people, “You cannot serve the LORD, for he is a holy God. He is a jealous God; he will not forgive your transgressions or your sins.

Contemporary English Version
Joshua said: The LORD is fearsome; he is the one true God, and I don't think you are able to worship and obey him in the ways he demands. You would have to be completely faithful, and if you sin or rebel, he won't let you get away with it.

New American Bible
Joshua in turn said to the people, “You may not be able to serve the LORD, for he is a holy God; he is a passionate God who will not forgive your transgressions or your sins.

Douay-Rheims Bible
And Joshua said to the people: You will not be able to serve the Lord: for he is a holy God, and mighty and jealous, and will not forgive your wickedness and sins.

And Joshua said to the people: You will not be able to serve the Lord: for he is a holy God, and mighty and jealous, and will not forgive your wickedness and sins.

Ye cannot

Joshua 24:23 Now therefore, said he, put away strange gods from among you, and incline your hearts to the Lord the God of Israel.

Ruth 1:15 And Noemi said to her: Behold thy kinswoman is returned to her people, and to her gods, go thou with her.

Matthew 6:24 No man can serve two masters. For either he will hate the one, and love the other: or he will sustain the one, and despise the other. You cannot serve God and mammon.

Luke 14:25-33 And there went great multitudes with him. And turning, he said to them: . . .

holy

Leviticus 10:3 And Moses said to Aaron: This is what the Lord hath spoken. I will be sanctified in them that approach to me: and I will be glorified in the sight of all the people. And when Aaron heard this, he held his peace.

Leviticus 19:2 Speak to all the congregation of the children of Israel. And thou shalt say to them: Be ye holy, because I the Lord your God am holy.

1 Samuel 6:20 And the men of Bethsames said: Who shall be able to stand before the Lord this holy God? and to whom shall he go up from us?

Psalm 99:5,9 Exalt ye the Lord our God, and adore his footstool, for it is holy. . . .

Isaiah 5:16 And the Lord of hosts shall be exalted in judgment, and the holy God shall be sanctified in justice.

Isaiah 6:3-5 And they cried one to another, and said: Holy, holy, holy, the Lord God of hosts, all the earth is full of his glory, . . .

Isaiah 30:11,15 Take away from me the way, turn away the path from me, let the Holy One of Israel cease from before us. . . .

Habakkuk 1:12 Wast thou not from the beginning, O Lord my God, my holy one, and we shall not die? Lord, thou hast appointed him for judgment: and made him strong for correction.

a jealous

Exodus 20:5 Thou shalt not adore them, nor serve them: I am the Lord thy God, mighty, jealous, visiting the iniquity of the fathers upon the children, unto the third and fourth generation of them that hate me:

Exodus 34:14 Adore not any strange god. The Lord his name is jealous, he is a jealous God.

1 Corinthians 10:20-22 But the things which the heathens sacrifice, they sacrifice to devils and not to God. And I would not that you should be made partakers with devils. . . .

he will not

Exodus 23:21 Take notice of him, and hear his voice, and do not think him one to be contemned: for he will not forgive when thou hast sinned, and my name is in him.

Exodus 34:7 Who keepest mercy unto thousands: who takest away iniquity, and wickedness, and sin, and no man of himself is innocent before thee. Who renderest the iniquity of the fathers to the children, and to the grandchildren unto the third and fourth generation.

1 Samuel 3:14 Therefore have I sworn to the house of Heli, that the iniquity of his house shall not be expiated with victims nor offerings for ever.

2 Chronicles 36:16 But they mocked the messengers of God, and despised his words, and misused the prophets, until the wrath of the Lord arose against his people, and there was no remedy.

Isaiah 27:11 Its harvest shall be destroyed with drought, women shall come and teach it: for it is not a wise people, therefore he that made it, shall not have mercy on it: and he that formed it, shall not spare it.