Most homeowners require 20-30 years to pay off their loan, why is it different for our church?

We are in a very similar situation as most homeowners in that starting in January 2020 we will have a mortgage with a set payment schedule.  It is set up on a 15 year amortization schedule not 20-30 years but other than that, it is the same. The Dioceses of Kansas City / St.Joseph holds the note and we will be making monthly payments there.  

Most financial advisors tell their clients that it would be a very wise move is to pay more than the minimum mortgage payment when possible.  Why do they say that? It is because it shortens the length of time needed to payback the loan and the savings in real money is tremendous. 

Just look at how much we will save if we meet our goals[table “2” not found /]