Personally I regard that when someone is dead they do not need any protection, they do not exist anymore. It is not a real difference in how you care about your loved ones, as much as a difference in belief of what happens when we die.
As an atheist you do not believe in the survival of the mind after the death of the body in which the mind that is "I" has developed. While I believe that the inner life force that was in the first primitive earthly life form, has evolved on the spirits that had developed in all those life forms, and through and within the bodies of all my ancestors including my pre-Human ancestors, that indwelling life force has become who I Am.
Not only do we all share in the universal body, so too, do we all share the universal soul, and I also believe that my life is imprinted upon the soul (Universal animating principle) and after the body in which "I" the mind has developed is returned to the universal elements from which it originated, "I" who was created by the information taken in through the senses of that body and imprinted on the universal soul or the divine animating principle that prevades the entire universal body, will continue to protect my loved ones.