The seller's religion/believe system dis-allowed him from taking advantage of anyone by way of usury hence he felt it was unjust to benefit from the $40,000 in appreciation on the sale of his home.

A different religion?

We are instructed as investors and real estate professionals not to discriminate based on race, sex, religion, day of the week of birth, etc. 

I had a tenant years back insert their religion into nearly every conversation.

The Act prohibits discrimination in the sale, rental, and financing of dwellings, and in other housing-related transactions, based on race, color, national origin, religion, sex, familial status, and disability.

I know we cannot discarnate due to race, gender, disability, nationality and religion. 

My religion has always counseled its members to have a minimum of six months reserve in food, water, and cash.

For example, you can discriminate against smokers or dog owners but you cannot discriminate against someone based on religion or race. 

The Fair Housing Act - which applies to private landlords too - makes 'it is illegal to discriminate in housing on the basis of a person's race, color, national origin, religion, sex (incuding gender identity and sexual orientation), familial status, or disability." 

There are specific financial institutions set up for lending to museums that adhere to your religion, I suggest you start there, not sure if there are any here in Columbus Oh, but maybe where you are?