Foundation #3 Fruit of the Spirit is the yardstick.
In Galatians 5, Paul gives a couple of lists. The first list is the evidences that one is acting according to the sinful nature. The second is a list of the actions, attitudes and characteristics that are evidences of the Spirit of God's presence in our life.
I use these two lists to see if I am acting according my fleshly desires or if I am following God.
The first list has a bunch of negative characteristics and behaviors. Am I envious of some one? Am I angry about something that someone did to me? Am I worried about my position? Do I have feelings of hate for someone? etc... If I have to answer "yes" to any of these questions, I know that I am operating in my flesh; I am ME centered.
The second list is titled "the fruit of the Spirit". Am I at peace? Am I being gentle with those around me? Do I live with my emotions and other behaviors under control? etc... If the answer to any of these is "yes", then I know that I am operating according to the Spirit of God and acting like Jesus. (One interesting side note: this list describes the life that everyone wants - being at peace, being loving and kind, faithful, self controlled, etc. God designed us so that we would be fulfilled if we allow the Spirit to lead us.)
As I reflect on my behaviors, emotions and thoughts, I use these two lists to help me understand the root of my expressions: ME or the Spirit. These lists help me to understand when I am being obedient or disobedient and when I am reflecting me or Jesus to the world.
Check out Galatians 5:16-25!