Since the pastor is getting retired bitcoin shouldn't be the first plan. He is getting retired and where he normally make money from he won't be getting it again, that source is already close. It will be better for him to think about how to create income first either by doing business that can give him income everyday. If having a steady income is achieved then he can think of investing bitcoin. It does not make any sense that someone is getting retired and he is just making plans to invest bitcoin, the truth is that he is thinking bitcoin can be is next source of income or a career line to depend on.
Now are days churches are more business-minded than how they used to focus on only preaching and doing the work of God, which means that even if the pastor is no longer leading in that church as an active pastor, that does not stop the church from giving him his share of the revenue the church will be getting on a monthly basis. That being said, we can see that he still has a source of income.
If that won't work, he will still have those who will be coming to thank him with gifts and money that will sustain the family (those can also be considered as resources). If he really wants to invest in Bitcoin, he can also still do it and still have some money to set up a little business, which the family can be getting daily income from for their daily expenses.