Late in His Ministry Jesus made this statement:

I tell you, No: but, except you repent, you shall all likewise perish. - Luk 13:3 Though it is not the Lord's will that any perish, it is up to each individual to determine their fate.

So it appears repentance is pretty important.   What does it mean to repent?   
Definition: To change your thinking.   To change direction.   
The word repent in the Greek is metánoia.   

Jesus told us that our thinking is wrong- that it is what is causing all of our problems.   

What caused our wrong thinking?   The Sin Nature that formed in man in the garden.   

1. The first and most basic area of wrong thinking is about our Creator.   His nature, character, purposes and expectations were completely misunderstood when Jesus began His ministry.   

   The God that the pharisees taught was an exacting, harsh, angry God who had to be placated by righteous human performance in order to receive any kind of blessing from Him.   

   Jesus showed the true nature of the Lord by healing all who were sick, by forgiving all manner of sin and by liberating all who were in captivity - freely .   

   John 3:16,17 clearly state the truth about the Lord's love and will for mankind.   

2. The second important thing that Jesus told us to repent about is sin.   

   Jesus stretched the definition of sin to include even wrong thoughts!   He purposely brought condemnation upon all those who were striving for performance based righteousness.   

   Performance and animal sacrifice are inadequate.   The blood of Jesus and only the blood of Jesus can take away sin.   

3. The third important thing that Jesus told us to repent about is unbelief.   

   Jesus made it perfectly clear that unbelief is unacceptable - that it is the enemy of the Lord and man.   

   The will and expectation for good is how heaven operates.   Unbelief does not understand the Lord's good wil and as a result does not expect good to manifest.   

   Jesus taught us to expect salvation, good health, freedom, victory, power, love, joy, peace...etc.   to manifest in the Physical Realm because it had been willed in heaven.   

   This is having faith in the Grace of our Lord through Christ Jesus.   

4. The fourth important thing that Jesus told us to repent of is our self image.   

   In the Old Testament the Jews were referred to as children of Abraham and, most often, as children of Israel.   

   In David's writings he used the imagery of shepherd and sheep to show the relationship between God and man.   

   Jesus told us to refer to the Lord as our Father.   This represented a monumental change in the relationship between the Creator and man.   

   The relationship the Lord had with Abraham and His promises to Abraham are what sustained the children of Israel for two thousand years.   

   The Lord does not want us to have second hand relationships with Him!   

   In the shepherd-sheep imagery we see God as a different species than man just as the shepherd is a different species from the sheep he tends.   

   Our Father does not want us to dumbly depend on His care with no hope of ever becoming more than a sheep.   He has made us His Children through the New Birth.   

   We are now Sons!   We are filled with the Holy Spirit!   We may come boldly to the thrown of Grace.   We are a royal priesthood.   

5. The fifth important thing for us to repent about is prayer.   

   Jesus showed by example how prayer is supposed to work.   

   Jesus spent time in the Word, meditated on the Word, prayed for wisdom and revelation in the Word.   His prayer life was one which invited the Father to manifest the Word in His body.   

   Jesus prayed to prepare Himself to be able to operate in the Holy Spirit and the Word.   His time in the wilderness before he began His ministry was the most significant time of prayer in His life but there were no doubt many other instances.   

   But once He was prepared, He spoke and did the will of the Father - without asking the Father to do anything .   
   He taught with zuthority.   He commanded demons to leave with authority.   He healed with authority.   He forgave sins with authority.   

   Contrast our Lord's example of prayer with that of the typical Church person today.   Most prayer is one of petition for specific needs, often coming across as begging God to do something.   

   Sometimes it even sounds like the person praying is ordering God to do something.   

   Jesus never begged His Father to do anything or commanded Him to do anything.   

   Jesus told us to ask and receive, seek and find, knock and see the door opened.   

So, the question is: Have I truly repented?   

Luke 13:3 tells us that we will perish if we don't repent.   Jesus was not threatening us with hell-fire because the gift of our Father is Eternal Life - Himself.   But He was telling us that failure to repent will cause us to fail to experience Abundant Life which was His purpose in coming to earth.   

James 1:8 tells us that a Double Minded man is unstable in all of his ways.   

We all need stability in our lives.   The solid rock of Christ Jesus, the written and incarnate Word Of God, is our foundation.   But our minds must be transformed through heart-felt repentance before we will see the manifestation of the power of the Holy Spirit in us.   

So, let us stop halting between two opinions and bring our mind and body under subjection to our spirit which is new and perfect.