Absolutely, I have had close friend who are Christians, Buddhists, Muslims, Hindus, and atheists. Life is very simple in my mind, because I have chosen to follow the path set forth in the Vedas (Books of wisdom), it is best to love all linving beings as spiritual parts and parcels of God. I do not have to agree with my friends, I love my friends because the accept me as I am, I accept them as they are, we all try to make ourselves better people and help other around us.
We get into fun discussions about religions and beliefs, but we always wish each other well. We pray for each other, well not the atheist, but that is still ok with me. I pray for everyone. I pray that we all (all living beings) make it home to Godhead/Krishna and find eternal happiness.
P.S. I am not saying that I like or condone everyone's actions. I believe that their karma will straighten them out in long run.