I am not very much into rituals as I find some ‘over’ draggy. It’s a personal issue but I would still avoid rituals with lots of chanting (other than Pure Land related ones, as it’s my focus of practice). The excuses I give are mostly lame. And at times, I try to pay for my guilt by just contributing some donations.
I have attended the three traditions’ ritual ceremonies before (though not every single possible ceremony). Every ritual has its significance, and many are conducted to help the more unfortunate beings who are suffering by offering blessings. Beyond this, they also offer the Buddhadharma. One does get to learn the Dharma from the chanted prayers, which encompass and express the compassion and wisdom of the Buddha.
Although it’s not true that all Buddhists have to attend every ritual ceremony that various Buddhist organisations hold, it is still good to attend as many as possible with sincerity and understanding. This is part of Dharma practice too. Repentance ceremonies are especially important for us living ones. As stated in the Avatamsaka Sutra (华严经), if the negative karma that we had created since beginningless time takes shape, the entire universe would not be able to contain it. One does not need to be an astronomy fanatic to know how big the universe is.
In layman’s terms, when the time is ripe for negative karma to ripen, it might come with a bang – a ‘Big Bang’. No pun intended. So, to prevent any astronomic catastrophe of cosmic proportions that shatter our lives, it is good to constantly reflect and repent for our past deeds, to avoid doing all evil deeds, to do as much good as possible, and to purify our minds with the Buddhadharma. We might not know what evil we have done in our many past lives, but we could and should stop filling that karmic black hole with more negativities, that eventually explodes later when things get super dense!
May you and your loved one be filled with happiness.