Lister identifies what he takes to be the core meaning of the historic affirmation of impassibility: that God does not experience sinful emotions, involuntary emotions, or emotions that are in some way unworthy of him. Here is some good reading on this important subject. This doctrine was used to combat heracy in the early church and proved to be an important part of the early Christians Biblical understanding of God.
Read and enjoy. Let me know what you think?
http://www.reformation21.org/shelf-life/god-is-impassible-and-impassioned.php
http://thegospelcoalition.org/blogs/kevindeyoung/files/2010/04/T4G-2010-KDY-v_2.pdf
http://paulhelmsdeep.blogspot.com/2013/09/god-both-impassible-and-impassioned.html
http://mereorthodoxy.com/beauty-impassible-god-god-emotional-teenager/
http://www.rpcbmt.org/DivineImpassibility.html
http://www.modernreformation.org/default.php?page=articledisplay&var2=637
http://www.spurgeon.org/~phil/articles/impassib.htm