Our wanderings are not wasted years

Numbers 33:1-2 (KJV)
These are the journeys of the children of Israel, which went forth out of the land of Egypt with their armies under the hand of Moses and Aaron. [2] And Moses wrote their goings out according to their journeys by the commandment of the Lord : and these are their journeys according to their goings out.

And Moses wrote their goings out according to their journeys. Moses perhaps thought that it was futile to write of this journey, as he considered it Israel's failure. But God still saw the need. It should be a joy for us to know that God does not consider our wanderings and even moments of our failures 'wasted years'. He records them and keeps track of them:
Psalm 56:8 (NASB)
You have taken account of my wanderings; Put my tears in Your bottle Are they not in Your book?
He uses even wanderings and our tears for His glory, and for our good. They are not wasted, but they are used to build our character, make us to know God, make us to understand God's grace, make us to repent of sins, or help others who are going through like situations:
Romans 8:28 (KJV)
And we know that all things work together for good to them that love God, to them who are the called according to his purpose.
Indeed, they were chastised by God for their disobedience through this wandering, but it still worked for Israel's good. It worked in the next generation godly fear and obedience to the Lord. The account of their wanderings was a sample for future generation to not follow. It also showed Israel that they are not righteous, and showed that it was not because of their righteousnesss they are inheriting the kingdom, but that it was only by God's grace. It was to do these things:
Deuteronomy 8:2 (KJV)
And thou shalt remember all the way which the Lord thy God led thee these forty years in the wilderness, to humble thee, and to prove thee, to know what was in thine heart, whether thou wouldest keep his commandments, or no.
So the forty years can't simply be said that they were wasted for Israel. It humbled them, most of all. It was for their own good. It showed how weak they were apart from God.

It is likewise with Christians. The moments of disobedience can't simply be classified as failures, though they are. God's sovereignty and providence was working even during those times, that God may prove us, show us our sinfulness and our weaknesses, and our inability to save ourselves. The wilderness sanctifies us, and make us to be cleansed from our own pride and self-trust. Therefore the wilderness years work out to be for our own good in the end. Not that we want to return to the wilderness, but through God's hand it helped us to be more conformed to the image of Jesus Christ. However, see the condition in Romans 8:28: this grace only applies to "them that love God". Though we fail and are sometimes disobedient and are foolish, and thus are thrown into the wilderness, those who are called according to His purpose do not give up loving God. This is not because of some will-power on their part to love God even during those years, but these love God because they realize that God loved them even through those years. These love God because God first loves them. Let us then not despair even when we have failed, but continue to love God, who loved us, and sent His Son to die for us.

Let us also not judge our brothers who are going through the wilderness, as though we know anything about what God is doing in them. It may be that God is doing a sanctification work in them. We must not cease to rebuke them and pray for them, but it is not for us to write them off as unbelievers. We so easily forget about the greatness of God's sovereignty and we write them off as failures. Not that we ought condone their sins, but God may have put them through the particular wildness for a reason. Peter had to go through his wilderness of denying the Lord thrice that God may reveal who He was apart from Christ's grace. Let us not condemn them, but pray for them and commit them to Christ. If God has called them, God will carry them through. They shall be restored.

By the commandment of the Lord. It must be noted that it was God who commanded Moses to record Israel's journeys. It was not Moses' idea to do this thing. As mentioned, Moses most likely saw no need for it. This writing did not originate from the mind of Moses. It is the same with all writings of the scriptures. They are 'God-breathed', meaning they originate from the mind of God, and written by His commandment. It was not written by a committee who sat around and said, 'Okay, let's write something about God'. No. It was written by God's command, out of His will, out of His own mind. As it is written:
2 Timothy 3:16-17 (KJV)
All scripture is given by inspiration of God, and is profitable for doctrine, for reproof, for correction, for instruction in righteousness: [17] That the man of God may be perfect, throughly furnished unto all good works.
2 Peter 1:20-21 (ESV)
knowing this first of all, that no prophecy of Scripture comes from someone's own interpretation. [21] For no prophecy was ever produced by the will of man, but men spoke from God as they were carried along by the Holy Spirit.
There is no other writing in the world that was produced by the will of God, and written by the Holy Spirit through men. The Bible was not written based on man's own interpretation or understanding of God. It was written based on God's own interpretation and understanding of Himself. There is no other script that is so alive with the life of God, for it is the only writing in the world that is of God, through God and is for God's glory. Scriptures are therefore some places hard to understand, for to really understand it one must have the mind of God, for it came from His mind. Scriptures therefore cannot be understood with a human mind. To the natural mind the bible appears foolish, for he tries to discern it with his own intellect. It does not work:
1 Corinthians 2:14 (ESV)
The natural person does not accept the things of the Spirit of God, for they are folly to him, and he is not able to understand them because they are spiritually discerned.
The bible must be understood by the help of the Holy Spirit, who is the Author of the bible. He who wrote the book understands most about what He meant:
1 Corinthians 2:11-13 (KJV)
For what man knoweth the things of a man, save the spirit of man which is in him? even so the things of God knoweth no man, but the Spirit of God. [12] Now we have received, not the spirit of the world, but the spirit which is of God; that we might know the things that are freely given to us of God. [13] Which things also we speak, not in the words which man's wisdom teacheth, but which the Holy Ghost teacheth; comparing spiritual things with spiritual.

Scriptures cannot be interpreted with human wisdom. It is like an animal trying to understand the things of human beings. Unless the animal is given the spirit of man, it will never understand the deep things of man. But God has given us the Spirit of God, and given us a spiritual mind, that we may understand Him through His word. Moreover, it is the through the scriptures that we understand scriptures. As God wrote no other holy writings, no other writing can be used as a proper reference for interpreting scripture. Spiritual things can only be compared with spiritual. As it is written:
Isaiah 34:16 (KJV)
Seek ye out of the book of the Lord , and read: no one of these shall fail, none shall want her mate: for my mouth it hath commanded, and his spirit it hath gathered them.
And as it is also written:
Matthew 18:16 (KJV)
in the mouth of two or three witnesses every word may be established.
We must only look at God's word through the lens of God's word. It is the word of God which bears witness of the word of God. One witness is not enough to establish a truth, but God has given us not only two or three, but, as it were, a cloud of witnesses that testify of the one Truth of the Bible, Jesus Christ. Not that God needed witnesses, for our Triune God Himself testifies of Jesus Christ, who is the Word of God:
John 8:18 (KJV)
I am one that bear witness of myself, and the Father that sent me beareth witness of me.
John 15:26 (KJV)
But when the Comforter is come, whom I will send unto you from the Father, even the Spirit of truth, which proceedeth from the Father, he shall testify of me:
Let us pray then that God fills us with His own Self and with the Word of God, that we may understand and know Him. All things have come forth from Him, and it must be that through Him alone we must also understand Him. Let us not rely on our own understanding when studying scriptures, but rely on Jesus Christ to be our Guide, for we are blind. Let us have Christ to be our eyes for us, that through Him, through the Word alone, we may read God's word and understand life.