Is there a fine line between assumption and discernment?

I pause here to remember fondly my friend mandovi, who has since ceased to post, but who sitting in a cafe in India with me one day put assume to me like this ASS-U-ME.

Yesterday in Church whilst the Pastor was speaking it hit me that what we assume shows us the condition of our hearts. I know the most gentle lady, I think she might just be the most gentle lady on the earth, who could NEVER assume anything bad about anyone. Honestly, I remember being annoyed at her sometimes b/c she NEVER would assume or think anyone had a bad motive, I mean EVER...yesterday I realized it was because my heart was not as pure as hers...and her outlook was totally a lot more postive than mine...
I want to be discerning...I long for that...I want my heart to respond out of pureness and start to assume the positive...God is constantly working and boy am I thankful! I told J last night that this week I am going to work on not assuming bad things...I think, ha ha KNOW, satan likes to play mental games with me...and this week, he is going down for the count baby! Yay for thought/spirit provoking Sunday School!
An update on Jonathan for all of you who want to know...things are just getting better every day... Oh, and I did it, I joined the Church I have been visiting since I got home...