How is it possible to help someone after they have died? What can you do for them? What would you give to be able to do something – anything – that will help them, that will lift them up (as it were).
In general, we don’t know very much about life after this life. We don’t know anyone who has been there and come back.
And yet, we know that Torah and Mitzvahs raise (give an aliyah) a soul (to a neshama) always. The neshama is forever. HaShem is forever. Torah and Mitzvahs are forever.
But one needs a living body to do Mitzvahs. Or better, a community (minyan) of lving bodies. Or better, a community (minyan) of living bodies praying in the holiest place on earth!
That minyan will be saying y’hei sh’mei raba for your beloved.