There were certainly Christian moneylenders in late medieval Europe, and in the case of Florence, banking was a major industry. Non-Christians (Jews) in Northern Italy around that time did some small scale lending in small towns, so if you needed some cash to replace a plough for example, you had source for that. The population of small Tuscan towns was quite protective of the Jewish families in their midst and sometime rebelled when the authorities wanted to expel them. The Christian bankers financed commerce and major transactions. So how did they do it without violating the biblical requirement not to charge interest?

So you cannot charge interest on a loan, but you can charge a fee to transport goods from one city to another. The goods could be a load of wool fabric, or it could be a sealed bag containing 1000 florins. Let's say that you ship that bag from Florence to Cairo, and that it takes one month for it to get there. You get charged a fee for the service. And then you need that bag of florins to return to Florence, again in one month and again paying a fee for the service. So in theory you had your gold coins moving from the local banker to their branch in Cairo and back in a 2 month period. In reality, all of that was done on paper, and there was no physical transfer. So the bank could lend you money without charging interest, and collect the fees for a "transfer" of 2 months. A bank branch in the Flanders may be used to do a shorter term loan since the travel time was shorter. Over time, the fiction of doing interest loans as transfers with fees became less critical to maintain, and more loan and banking products were then offered.

Goldthwaite - The economy of renaissance Florence is an excellent source for more information on how the banking industry started and evolved in renaissance Florence.