Heb 4:2, Ex 5:21, Ex 14:11, Ex 15:24, Ex 17:2-3, Ex 32:1, Num 11:4, Num 14:2,22-23, Heb 11:31, Deut 30:20, Rom 10:16-17

The Israelites who did not enter the land of Canaan in the Old Testament could not enter the land of Canaan, the land where Christ would come, because they did not believe in God's covenant. (Heb 3:18)

Heb 3:18 And to whom sware he that they should not enter into his rest, but to them that believed not?

Even now, those who do not believe that Jesus is the Christ cannot enter the rest of God. (Heb 4:2-3, Rom 10:16,18)

Heb 4:2 For unto us was the gospel preached, as well as unto them: but the word preached did not profit them, not being mixed with faith in them that heard it. 3 For we which have believed do enter into rest, as he said, As I have sworn in my wrath, if they shall enter into my rest: although the works were finished from the foundation of the world.

Rom 10:16 But they have not all obeyed the gospel. For Esaias saith, Lord, who hath believed our report? 18 But I say, Have they not heard? Yes verily, their sound went into all the earth, and their words unto the ends of the world.

The people of Israel did not believe in God to lead them. So they could not enter the land of Canaan in the end. (Num 14:22-23, Ex 5:21, Ex 14:11, Ex 15:24, Ex 17:2-3, Ex 32:1, Num 11:4, Num 14:2)

Num 14:22 Because all those men which have seen my glory, and my miracles, which I did in Egypt and in the wilderness, and have tempted me now these ten times, and have not hearkened to my voice; 23 Surely they shall not see the land which I sware unto their fathers, neither shall any of them that provoked me see it:

Ex 5:21 And they said unto them, The Lord look upon you, and judge; because ye have made our savour to be abhorred in the eyes of Pharaoh, and in the eyes of his servants, to put a sword in their hand to slay us.

Ex 14:11 And they said unto Moses, Because there were no graves in Egypt, hast thou taken us away to die in the wilderness? wherefore hast thou dealt thus with us, to carry us forth out of Egypt?

Ex 15:24 And the people murmured against Moses, saying, What shall we drink?

Ex 17:2 Wherefore the people did chide with Moses, and said, Give us water that we may drink. And Moses said unto them, Why chide ye with me? wherefore do ye tempt the Lord? 3 And the people thirsted there for water; and the people murmured against Moses, and said, Wherefore is this that thou hast brought us up out of Egypt, to kill us and our children and our cattle with thirst?

Ex 32:1 And when the people saw that Moses delayed to come down out of the mount, the people gathered themselves together unto Aaron, and said unto him, Up, make us gods, which shall go before us; for as for this Moses, the man that brought us up out of the land of Egypt, we wot not what is become of him.

Num 11:4 And the mixt multitude that was among them fell a lusting: and the children of Israel also wept again, and said, Who shall give us flesh to eat?

Num 14:2 And all the children of Israel murmured against Moses and against Aaron: and the whole congregation said unto them, Would God that we had died in the land of Egypt! or would God we had died in this wilderness!

Those who firmly believed in God's covenant entered the land of Canaan, the land where Christ would come. (Heb 11:31, Deut 30:20)

Heb 11:31 By faith the harlot Rahab perished not with them that believed not, when she had received the spies with peace.

Deut 30:20 That thou mayest love the Lord thy God, and that thou mayest obey his voice, and that thou mayest cleave unto him: for he is thy life, and the length of thy days: that thou mayest dwell in the land which the Lord sware unto thy fathers, to Abraham, to Isaac, and to Jacob, to give them.