John 10

The thief does not come except to steal, and to kill, and to destroy. I have come that they may have life, and that they may have it more abundantly. v.10

Read chapter 10
Many false christs came proclaiming they were the messiah to come (and it's still happening today too).  Jesus is explaining to His disciples how they will know who is the Christ.  By having to enter through the door, as Jesus is figuratively explaining to them, He is saying how the Christ has to fulfill every prophesy of the Old Testament, to enter in the right way and not climbing or sneaking in some other way (v.1).  These that do are thieves and robbers.  They're claiming to be the Savior for their own gain and care nothing about the sheep (the people Israel).   They're bloodthirsty.  They hate the sheep. Where Jesus came fulfilling all 200+ prophesies and came that the sheep would have life more abundantly, not just this life but what John's been referring to in previous chapters- that everlasting life.  Yet even that the life now would be life to the full- not making everyone perfect but life worth living.  Jesus says He is the door and only through Jesus is salvation and everlasting life possible.
How have you felt that abundant life with Jesus in this life?  What thieves and robbers do you see in the world today deceiving people to think that they're God?