This is a great question. There are several ways in which the Renaissance impacted the Reformation. Let me give you two answers. First, the Reformation was an religious intellectual movement. Much of the intellectual power was obtained by the gains of the Renaissance. For example, religious reformers like John Calvin and Zwingli were people who were trained in classical philology. They knew their Greek and Latin well. In fact, Calvin's first academic piece was a treatise on the Roman philosopher Seneca.
Second, there was a buzz word during the Reformation, "ad fontes." This was a Latin phrase, which meant "back to the sources." So, the Reformers bypassed the layers of commentaries from the Medieval ages and went back to the classical world and early church fathers. This idea was an outflow from the Renaissance.