The time period when banking and money-lending, around the XIII century, was a moment where European economies had entered a period of evolution, resulting in an economy much more ample and complex that the one from two centuries prior. Advanced banking techniques which we think of as simple, like letters of credit and loan interests, were born of a much greater availability of money - literal money, minted with greater access to precious metals, especially silver.
Political situations were also changing, with a gradual abandoning of the mostly enclosed, land-based economies centered around castles in the rural areas subject to vassal or lordly authority. Cities, which had begun their expansion both physically and politically, multiply in importance and number. Jacques Le Goff dubbed this period the «happy century for money».

Merchants become richer and more important, necessitating the aforementioned financial tools to serve their continental interests. I say continental because major banks mostly centered in Florence and northern Italy and in German cities, start creating branch offices in all the other centers of trade. For example, in a lot of European capitals there's one road called "Lombards' Street", named after Florentine merchans acting as bankers in that very road, as we know Italians were, for a time, the first to create and export said financial tools.
Merchants served ad bankers, investors and traders. This immense wealth moving around Europe (once again, literally, as a merchant from Pavia could go at his local Florentine bank branch office, sign a letter of credit to be sent to another of his associates in Bruge, and used to pay a shipment of furs of a Russian merchant which could use the letter of credit to withdraw said money in Lubeck's branch of said bank), stimulated and sustained the economic growth of these centuries, especially through mercantile investments for long range trade operations, with merchants sharing costs and profits of an expedition, often signing insurance warranties, split among the partecipants to this endeavor. Entities such as the German Hansa do find their origins within this climate.
This period also saw the gradual increase of salaried jobs both in agriculture and proto-industrial jobs, such as the wool industry in Florence.

Thus, banking and bankers started becoming very, very important also on a political level. Wealthy bankers would loan large sums of money to kings and rulers to fund their wars, or to even out the kingdom's budget by withdrawing this amount of money and repaying it with donations or credit to be exact from, say, tolls of a specific kind (in Naples during the 1300s this could be the case of the salt tax). These people also participated in auctions of public contracts, providing the money up front, maybe with a margin beyond the proposed amount, and were paid back with the income of said contract. For example, in Capua during 1477, a merchant was repayed with the incomes of the tolls collected by a court of justice.
The political fight within center and northern Italy during the XIII-XIV centuries, especially in Tuscany and Florence, was heavily centered around these powerful bankers as they were the ones providing funds for the Papacy, helping cement the city's allegiance with Rome.

Historians are divided if capitalism has begun in this period.

It also happened that some merchants began getting canonized. Omobono Tucenghi (first half of the 1100s-1197) was a merchant from Cremona, described as being a rich but very pious and religious man, dedicated to charity. In earlier times, merchants risked being associated with the same dishonesty of usury if they didn't donate their wealth back. Omobono did this, to the point of being canonized as a saint in 1199.

Out of necessity, the Church's perspective on the matter began to shift as well, as this practice while still regarded with mixed feelings, was too important to condemn outright.
Until the XIV an XV centuries, usury was both a spiritual and natural sin, as it implied the trade of both time (a commodity only God could provide) and money, given the assumption of Scholastic theologians and philosophers that: "money doesn't generate other money" (nummus non parit nummos). Usuraries were to be denied a proper burial, and their only hope was to return the interests on the loans, either in life and in death through testaments.
The new stance was focused on the conception of the correct interest behind a loan, towards not bleeding dry a fellow Christian and still repaying the wordly luck by donating part of one's wealth into charity. It's interesting the headline found in the books of the merchant Francesco Datini of Prato (1335-1410), reading: "In the name of God and profit". It was also born of the sincere feeling of bankers and other persons loaning money towards charity and the salvation of their souls, paired with the Church's target to save the souls of all the members of the community, even the ones of usuraries. These factors concurred in the creation of the Purgatory, by all means a place of transition where even usuraries could wait in order to ascend to Heaven.

I hope this answers your question.