Spreading a message
The message that Jack wanted to spread was that people should go to cemeteries more often and show their respect. One day, unfortunately, we are all going to end up there in some shape or form. So it is important to not disrespect the memories of the people that are buried there.
Who knows when our time will come, but it’s nice to know that even after we are gone, someone is still looking out for us. Making sure that our final resting place is not disrupted or damaged in any way. This can ensure that we can pass on to the afterlife in peace and harmony.