Weighing People's Worth on a Scale

In a deep and surprisingly emotional conversation with a dear friend yesterday, I realized a common natural system of weighing a person's value to us (and to society in general) is by a scale system. We often take all of a person's good deeds and place them on one side of the scale. We then take all of their weaknesses and place them on the other end of the scale and we see which side comes out on top. As I realized this is how I had felt my friend had measured me, I realized how fragile our friendship was. If by some slight error in calculation, my weaknesses and frailties would outweigh my goodness. That would then run the risk of negating our history - all the time spent together, all the experiences, all the conversations - no longer valid because I was ruled to be a "bad person" not solely in situation, but in essence. What a fragile relationship is then created by such a measurement of people. Is this love? Is this Christ-like charity? I somehow can't believe it is. Somehow we must find a way to love people including their weaknesses.