Preparing in order to help our neighbor is one thing because it is done out of love.
Whereas I find the hoarding and prepping mania is very fear and ego based and shows a lack of faith that we are counting on our own means and devices to survive whatever is to come.
I must admit I fell prey to this thinking at one point as I had a lot of outside sources pressuring me to ‘stock up’.
God will provide for his children… think about the loaves… the fish… recent elders even describe overflowing pots of food wherein they only put a half a cup of grain.
Saint Matrona even described in the last times that we will take dirt, form them into little balls, pray and they will become edible!
St. Matrona's prophecy is regarding the time of the Antichrist, when the confessors of Christ will flee into the wilderness, so I don't know if it would be wise to try it now. For one thing, I'm not sure if any of us have faith enough to turn dirt into food. Anyone confessing Christ when the Antichrist is in power will probably have much greater faith than we do.
Our ancestors would store food to last until the next year's garden could feed them because they couldn't go to the grocery store for food. We would be wise to do the same. In the near future we also may not be able to find and afford food at the grocery store. I agree though that we should not hoard food for the next 20 years, as some do. Prudence is one thing, fear is another!
St. Paisios recommended, "So if you can now learn to live simply and frugally, you will be able to get through these difficult years. It will be helpful to have a small field, to cultivate some wheat or potatoes; to have a few olive trees, and then with some farm animals, a goat, a few chickens you will be able to provide for the needs of your family." (Volume II of his Spiritual Counsels series)
In the chapter on the Signs of the Times, St. Paisios talks about both the times we are in now and when the Antichrist will come. These two time periods are very much linked. The satanists controlling our governments are making a big push to bring about one world government and the reign of the Antichrist. Our Christ is going to "slap them down", as St. Paisios says, so that Christians will have time to get into better shape before the Antichrist appears. As Elder Justin says, we are very weak now. We have to do better and help our children to do better. They or their children may be the martyrs of the end times.
I haven't seen any books in English about Elder Justin Parvu, unfortunately. The Orthodox Talks website has a page on him.
https://www.orthodoxtalks.com/elder-justin-parvu/. Here's a quote from Elder Justin, "Therefore, please stop looking for solutions. Human solutions are not existent, my dears! The solution is to die for Christ."