I have read this passage of scripture many times over the years, but I don't believe I have ever fully realized what these new and old commandments are that John is referencing. I knew that John was referencing the love of Jesus, but have never taken it much further. I did some additional reading in my trusty online commentary and found that John is referring to the commandment in the Old Testament of "Love thy neighbor as thyself." and the commandment in the New Testament of "As I have loved you, so you must love one another." (John 13:34 NIV)
Before Jesus spent time on this earth there was really no comparison of how to love except for the way a person loved himself. However, with the birth of Jesus, his death and resurrection, the world saw a new kind of love. The love that Jesus has for each one of us. A love that loves us when we don't deserve to be loved. A love that loves us when we are not lovable. A love that is sacrificial. Sacrificial even to death on the cross.
As Christians, we must have this kind of love to walk in the light of God. We must be able to love rather than hate. We must be able to forgive instead of holding on until it makes us bitter ourselves.
Showing this kind of love is one of the ways we can show the world we are Christians. There are many people out there that don't understand forgiveness. What a wonderful way to show them what God can and will do for them if we have hearts full of forgiveness for our fellow man!
Once again John has showed us how we can walk in the light of God rather than the darkness. My prayer today is that each of us will choose to love with the love of God... a love that forgives, a love that is unconditional, a love that is sacrificial.