medieval cristians were not against all lending. Templars lent to governments as a way to raise funds. Regine Pernaud tells about a Bishop intervening to expel from the  land a farmer who did not pay his debts. Generally proto-banks existed in small scale. Kings borrowed $ to go to war. BUT:

* coins were gold or silver. No inflation risk. You lend 10 coins, if you receive back 10 coins after 1 year, you have only lost oportunity cost. It is very different from lending 10 dolars to get 10 dolars back after 1 year - who knows how much the dollar will be worth then?

* oportunity cost was generally lower than today (slower and less diverse economy, smaller population, diffcult transportation, etc.) 

* there were acceptable rates, Pernaud again tells about 3% to 7% / year depending on where/who/when. 

And lenders charging more, (~10-15%) would be considered usurers. With some reason given the above points. 

Albeit... some agitation or even violent events against usurers (not only Jews) appear to have been instigated by people who borrowed and did not pay... 

in renassaince times all shame is lost... 1519 imperial election was a borrowing orgy.. the candidates were bribing the electors. And it was larger but not the first time electors were bribed. 
To expel the Dutch from Brazil in 1650, Portugal got indebted for generations...