Deuteronomy 1

After many years in the wilderness, as Moses and the children of Israel make their final approach to the promised land, Moses recounts how -

"...the LORD thy God hath set the land before thee: go up and possess it, as the LORD God of thy fathers hath said unto thee; fear not, neither be discouraged."  (Old Testament | Deuteronomy 1:21)

But then reminds the people -

"...ye came near unto me every one of you, and said, We will send men before us, and they shall search us out the land, and bring us word again by what way we must go up, and into what cities we shall come.
23 And the saying pleased me well: and I took twelve men of you, one of a tribe:
24 And they turned and went up into the mountain, and came unto the valley of Eshcol, and searched it out.
25 And they took of the fruit of the land in their hands, and brought it down unto us, and brought us word again, and said, It is a good land which the LORD our God doth give us.
26 Notwithstanding ye would not go up, but rebelled against the commandment of the LORD your God:
27 And ye murmured in your tents, and said, Because the LORD hated us, he hath brought us forth out of the land of Egypt, to deliver us into the hand of the Amorites, to destroy us.
28 Whither shall we go up? our brethren have discouraged our heart, saying, The people is greater and taller than we; the cities are great and walled up to heaven; and moreover we have seen the sons of the Anakims there.
29 Then I said unto you, Dread not, neither be afraid of them.
30 The LORD your God which goeth before you, he shall fight for you, according to all that he did for you in Egypt before your eyes;
31 And in the wilderness, where thou hast seen how that the LORD thy God bare thee, as a man doth bear his son, in all the way that ye went, until ye came into this place.
32 Yet in this thing ye did not believe the LORD your God..."  (Old Testament | Deuteronomy 1:22 - 32)

Thus, the Lord had them wander in the wilderness until that generation has passed away.  Now with this generation of greater faith, Moses recounts what recently happened which would have happened years before had that generation had greater faith where the Lord said -

"....Behold, I have begun to give Sihon and his land before thee: begin to possess, that thou mayest inherit his land.
32 Then Sihon came out against us, he and all his people, to fight at Jahaz.
33 And the LORD our God delivered him before us; and we smote him, and his sons, and all his people.
34 And we took all his cities at that time, and utterly destroyed the men, and the women, and the little ones, of every city, we left none to remain:
35 Only the cattle we took for a prey unto ourselves, and the spoil of the cities which we took.
36 From Aroer, which is by the brink of the river of Arnon, and from the city that is by the river, even unto Gilead, there was not one city too strong for us: the LORD our God delivered all unto us:"  (Old Testament | Deuteronomy 2:31 - 36)

"THEN we turned, and went up the way to Bashan: and Og the king of Bashan came out against us, he and all his people, to battle at Edrei.
2 And the LORD said unto me, Fear him not: for I will deliver him, and all his people, and his land, into thy hand; and thou shalt do unto him as thou didst unto Sihon king of the Amorites, which dwelt at Heshbon.
3 So the LORD our God delivered into our hands Og also, the king of Bashan, and all his people: and we smote him until none was left to him remaining.
4 And we took all his cities at that time, there was not a city which we took not from them, threescore cities, all the region of Argob, the kingdom of Og in Bashan."  (Old Testament | Deuteronomy 3:1 - 4)

Og was one of those giants (sons of the Anakims) the spies had years before said they could not overcome.  The spies had even suggested that the cities had walls over which they could not overcome and yet now Moses makes the point -

"All these cities were fenced with high walls, gates, and bars; beside unwalled towns a great many.
6 And we utterly destroyed them, as we did unto Sihon king of Heshbon, utterly destroying the men, women, and children, of every city."  (Old Testament | Deuteronomy 3:5 - 6)

The lesson is that when the Lord commands and tells us to be not discouraged, He is with us and we will succeed.  If we do, we will not be caused to wander.