Our Scripture reading today is Luke 15:4-7.
Verse 7, "I say unto you, that likewise joy shall be in heaven over one sinner that repenteth, more than over ninety and nine just persons, which need no repentance."
As we read these verses, we cannot overlook the theme of joy.  It is mentioned in three consecutive verses.  Why is there joy?  A lost sheep has been found.  There is joy for one lost sheep even though he still had 99 safe and sound.  The shepherd has joy and he shares that joy with his friends and neighbours.  The Lord Jesus is teaching us something in this parable about the importance of one lost sinner getting saved and how we should respond.
I wonder the last time you heard of someone getting saved, what was your reaction?  Did you even have a reaction?  Just recently, we had a dear lady come to know Jesus Christ as her personal Saviour.  Do you know what that means?  She is no longer headed for hell!  She has eternal life as a present possession!  I will tell you the moment she received Christ in my office, there was clapping and rejoicing by her friend that invited her to church.  In addition, we are told in verse 7 of our text that there was joy in Heaven.  It would be a good idea to rejoice about what Heaven rejoices about.