Many Christians know the call to Repent - Repent, for the kingdom of heaven is at hand. - to be most associated with John the Baptist. However, Jesus also proclaimed it - "From that time on Jesus began to preach, 'Repent, for the kingdom of heaven has come near.'" (Matthew 4:17)

The word that Jesus was using for Repent, as He walked the roads of Israel so many years ago, is metanoeo (met-an-o-eh-o), meaning you think differently, you reconsider. This word is a compound word (two words forming one). The first word is meta meaning hereafter. The second word is noieo meaning think differently. So, when you combine the two you have Hereafter Think Differently - Metanoeo.

Repentance and Forgiveness are not the same, BUT they do travel hand-in-hand wherever they go. First, there is a consideration in the mind of change, then there is the ascent of the decision in the mind by coming to God and accepting His gift of Salvation by asking for Forgiveness. You have got to realize your problem (repentance) before turning to God's answer - Forgiveness through Christ. "Repent, then, and turn to God, so that your sins may be wiped out, that times of refreshing may come from the Lord," - Acts 3:19 Remember what Christ said about considering first?

"Suppose one of you wants to build a tower. Won’t you first sit down and estimate the cost to see if you have enough money to complete it? (Luke 14:28) Or suppose a king is about to go to war against another king. Won’t he first sit down and consider whether he is able with ten thousand men to oppose the one coming against him with twenty thousand?" (Luke 14:31)

When you "sit down and estimate" or "sit down and consider" - you are repenting.

The decision to follow Christ is one kind of Repentance that will influence the rest of your life. That repentance should carry with it the display of a Christlike lifestyle. However, this does not mean we stop repenting or thinking differently. Christians are still imperfect. 

After receiving Christ as our personal Savior we are not sinless, but we should be recreated to sin-less. Within our Christian lifestyle there will be many opportunities to change your mindset about matters. What you may have thought about a given situation will be approached differently because like the original word that Jesus used - metanoeo (met-an-o-eh-o), you think differently, you reconsider, you filter your thoughts through The Holy Spirit first, you Repent.

I have heard it said that to repent is to turn 180 degrees in a given situation. However, who is to say that the direction you would be turning in is the correct one. The differing mindset cannot be just any ole 180 degree turn. I can turn around on a given matter and leave God out of the picture. 
For the non-Christian it means changing your perspective from a worldview to how Christ sees you - forgiven through His sacrifice and victory. For the Christian it means you filter your thoughts through The Holy Spirit first. True repentance hands over all ideas, thinking processes, dreams, imaginations, sub-conscience and conscience thoughts to God. It All Starts In Our Mind.