If God is a God of reconciliation...then who am I serving?!?!

  I wanna believe we serve a God of reconciliation.  That God can take even the most hardest hearts and turn them back to Him and back to each other.  But, what happens when one of those hardened hearts is my own and I'm no longer sure if I want reconciliation?!
  Tonite at dinner my mom informed me that one of my sister's is thinking about starting to attend my church.  Now if I was a "good little Christian" (or at least acting on my best behavior as I so often do in Christian circles), I would be excited about the idea of seeing my sister come to God or even just church.  She's gone through a lot over the past several years and if she truly understood the grace of God it would change her life.
  But instead, once again, my ugly side reared it's head.  It seems lately, all I've been doing if showing my faults.   I feel so overwhelmed lately by my lack and in that moment of my mom sharing this information about my sister with me, I was once again faced with how jaded I truly am.
  To be honest, I'm not sure I'm ready to move forward with my sister....to forgive her...and to begin to once again to give her the benefit of the doubt.  It seems like every time I do that I set myself up for disappointment  and I've had enough of that over the past several weeks.  And yet when I think about her coming to my church, I realise that my heart is completely opposite to the heart of God.  If God is a god of reconciliation...then who I am serving in this situation?!?!