Italy was not a unified country and and each state had rulers that were vastly rich since they were often involved in trading or banking or similar prolific endeavors. They invested this money into art because they liked it and they commissioned numerous pieces of art from famous artists of the time and enabled them to create whatever they wanted.
The concerns were about how to present the vast human experience and be adventurous and also to live in the moment and help people develop. The ideal was to show the greatness of humanity which is innate in humans. They were also concerned about how the church was affecting people and believed that people need to be educated and creative and think for themselves which was difficult at that period.
Renaissance art reflected humanist concerns by putting regular humans front and center with all their knowledge and experience. It was no longer about the church like it was in the medieval period but more about humans who achieved great things. They also connected themselves with ancient Greek and Roman artists through their works and created a new style that resembled their style in its respect for the human form and the human mind.