As physical beings, we are nothing more or less then any other animal. Just skin and bones and blood. From dust we came and to dust we will return. If any theological rendition of Creation is even near being accurate, then we are all brothers and sisters and every act of ill will we commit toward one another is a sin against God. Remember Jesus's added command; "Love one another as I love you."
For Christians, Jesus gave us the words to say when praying to God the Father. In the Lord's prayer we ask God to "Forgive us our trespasses..." with the condition...."as we forgive those who trespass against us." There is no "God is on your side or God is no my side", God just IS. We cannot be forgiven if we cannot forgive.
So, if we expect to be forgiven for our condemnation of anyone else, we must forgive those who we condemn for the very thing we are condemning them of. We all deserve a place on Earth to live in relative peace with one another. That is the promised land on Earth. That, we have to earn by being able to forgive one another our trespasses.