What is RIP:* Rest in Peace
The person is died, he has to wait until the judgement day in the kabar or in the coffin underground, as said in Abrahamic religions. Please research: "When is it going to be the judgement day." Not happened or happening any soon. But at the same time, they say the coffin getts dissolved into the earth roughly in 99years. So after certain years if the land is needed it can be reused for other purpose after those years. Just think again. In that case what about his wait for the Judgement day.
*Now for the person who passed away and goes through the funeral process:*
When the Soul have left the body, The body has to go back into the 3 basic elements of the nature (Air, Water & Soil). The funeral process is what complete this process. As mentioned in Sanatan Dharma & has been adopted, practised from more than 10 thousand years.
*In Future* Please respond wisely & don't follow the western customs saying RIP without the knowledge, otherwise at some point our kids will forget our own custom, culture, religion & values.
*God is Omnipresent*
This Nature around u, is God.
The process continuously running within you is the presence God.
God is not in One Person ..