From what I've read, the biggest "secrets" to longevity seem to be keeping your stress levels low and having a support network/family/group. Prayer usually implies someone is religious and religious people tend to be in social gatherings long into old age, chocolate and cigarettes can help alleviate stress (though I don't recommend smoking to curb your stress, haha, just saying for some people it does relax them).
Just my advice as someone from a public health perspective, if you want to live a long time
1) stay active as long as possible - you don't need to be a marathon runner, just make a point to not sit down all day. Go for walks with your dog or go hiking with friends, etc
2) Be involved in your community. Join clubs, groups, go to church if you feel inclined, etc. I teach public health classes and most of the people who attend are senior citizens - and you'd be amazed how active some of them are. One couple has a different club or activity every day of the week. Gardening club, walking club, church socials, light fitness classes, etc. But being social and having a group of friends and family to fall back on is important no matter what age you are.
3) Try not to worry about it too much. We all die, sadly, and no matter how long we live we'll all end up in the same place eventually. You'll notice that most of the people who live these long lives are all rather carefree - they don't seriously wonder how they've lived so long, they've just lived. And if you aren't lucky enough to live > 100, at least you've had a carefree life in the process.
4) Get your annual checkups. This is more a PSA as a public health official than anything else, but seriously, your annual physicals and bloodwork are extremely important, especially once you hit middle age (but EVERYONE should get them EVERY YEAR), it's the only way you might catch a potential problem, whether it be diabetes, hypertension, heart disease, cancer, etc. You can't catch everything, but you can catch a lot.
5) Genetics. Sorry you can't do much about it, but some families are just more proned to disease than others. Alzheimer's and colon cancer run in mine.