Three minutes without oxygen,
Three hours without shelter,
Three days without water,
Three weeks without food,
Three months without hope.
This is an axiom, not hard and fast statistics, of course. I walk around for hours outside without shelter and don't die!
The saying reflects general types of emergencies:
1. Drowning, strangulation, some medical conditions
2. Hyperthermia, hypothermia
5. Depression, despondency
The purpose of preparedness is to head off these sorts of situations altogether, if possible, and to give us the tools, skills, and wisdom we need to deal with these situations if and when they do occur.
We live in a fallen world. We are surrounded by sinners; some saved by grace and many more, not. Bad things happen in everyone's lives, eventually. Sometimes, no matter how prepared you are, when the proverbial "Stuff Hits The Fan", there's little you can actually do. Sometimes, your skills, tools and/or wisdom will save lives.
At this point, we're beginning to collect the skills, tools and experience that will help us survive an emergency or, like Joseph, weather hard times to come.
"Trust in the Lord with all of your heart and lean not on your own understanding;
In all your ways acknowledge Him and He shall direct your paths." Proverbs 3:5-6