I have done so at the grave of my mother, and with all my heart: "Mom, please pray for my boys, your grandsons." I am confident that she is in heaven, that she loves us, that she prays for us though of course she's not canonized. She trusted God all her life; He would not abandon her.
Nevertheless, if (hypothetically) she were a damned soul, my prayers were not wasted. No prayer is ever wasted. God hears every prayer, even the unspoken ones. Surely you know that.
Nevertheless, if (hypothetically) she were a damned soul, my prayers were not wasted. No prayer is ever wasted. God hears every prayer, even the unspoken ones. Surely you know that. I do not believe God listens to prayers to other people, dead or alive...I do not believe God listens to prayers to Allah or any statues or idols...
God listens to prayers to God...