may you rest in peace; I pray for your happiness in the afterlife
Formal condolence expression used when speaking to the bereaved or at funerals. Often followed by more humble variants like いたします or 申し上げます in very formal settings.
See also: 冥福を祈る
I sincerely pray for your happiness in the afterlife.
I humbly pray for your happiness in the afterlife.
Polite set phrase combining ご (honorific prefix), 冥福 (happiness in the afterlife), を (object marker), お祈りします (humble form of 祈る, 'to pray').