It's funny how much the grammatical structure of a sentence can alter the way it reads. "But the fruit of the Spirit is love." Not, but the fruits of the Spirit are. This reads as love being the fruit of the spirit, and then it goes on to list attributes of love. It's as if there should be a semi-colon after love, not a comma. So the evidence of the Holy Spirit being in someone is the presence of love, which manifests itself under the appearances of joy, peace, longsuffering, gentleness, goodness, faith, Meekness, and temperance. The only perfect human example of these attributes is Jesus. Oh, how far we fall short of His example on a daily basis. This comparison is not presented with the intention of condemning, but for the purpose of exemplifying how much we as humans need grace that only Jesus can dispense.
Now that we have isolated the different qualities that are evidence of Love and the Holy Spirit, it is necessary to take a close, but not to close, look at each one. Joy, happiness is fleeting but joy is eternal. Peace, something that cannot be found apart from God. In war or in a time of silence, there is no peace apart from God. Gentleness, it seems self-explanatory, but I would argue the opposite. Gentleness can be placed under a purely physical connotation, but I believe it is far more meaningful when displayed through words. Look at how gentle Jesus was with Peter in John 13. Instead of getting frustrated with Peter's zeal and defiance, He was gentle. Goodness, being and doing good without any prodding or hope of an earthly reward. Faith, giving your life for Jesus is faith. To see the big picture of eternity as God has revealed it to us and to live accordingly; that is faith. Meekness, to not boast in self. To let your self be hidden behind Jesus. That when you converse with someone, they might see Jesus in you, not the hideous thing that is you. Temperance. I would argue that this trait can be best expose when someone is treated unjustly, and does not return evil for evil. How often do we let our pride rear it's ugly head. We can see all of these traits so clearly when we look at Jesus, my hope is that someone might catch a glimpse of them in me.

The absence of any one of these traits is the presence of their antonym, which is sin by nature. I will dedicate a ten minute slot of prayer each morning to asking God to help me better exemplify these traits in my life.