It's difficult to put all of these elements in a line because they are more interdependent. In addition, if one of any of these things hadn't happened, the West would not have changed as dramatically. One thing is for certain--Gutenberg's printing press spread the other three's ideas far and wide and far into the future. The ripple from the printing press is still felt today. First, if there hadn't been any innate Renaissance curiosity in a few individuals, no one would have printed the classics from antiquity, or even researched them. Some very pivotal figures not mentioned in class were the Medici family. They were great commissioners in the pursuit of knowledge and the production of art in Florence at the time. Also, a growing middle and merchant class helped foster more time for intellectual and leisure pursuits.
Gutenberg is a Renaissance Man even though he was a humble tinkerer. What makes him so is the spirit of invention and experimentation and almost an artistic naiveté about his work. Many experts think that Gutenberg had absolutely no idea about the ramifications of his invention.
Once the printing press was invented and the classics were disseminated, ideas about humanism, democracy, and artistic, architectural, and scientific knowledge began to flourish. The ancient philosophy of Humanism revived in the Renaissance created a new relationship between man and God, threatening the hegemony of the Holy Roman Catholic Church that was becoming progressively "humanistic" in its pursuits. The Church was looking out for its finances and other interests and becoming wealthier and wealthier as people began to believe they had more determinism over their own lives and that disasters, disease, and troubles were more a product of nature or human choices and less a part of God's mechanistic game plan with human lives (from the medieval mindset). The environment became ripe for a Reformer, who, while he'd never admit and possibly adamantly deny, was just a part of the Humanist spirit as any of his Humanist contemporaries. Martin Luther questioned under threat of death, the motives of the Holy Mother Church that had been established for over 1000 years before him. This maverick and rebellious attitude and his ideas that basically "democratized" salvation took out (a) supervisor(s) in the individual's pursuit of salvation, and focused on the free gift of grace for all, not just a few and not with mindless rituals. These ideas are the essence of Humanist philosophy: individualism in the pursuit of salvation, individual worth of every human being independent of a human authority (grace), and an intellectual expression of the tenets or principles of his ideas. As a result of his timely rebellion, the Christian church was no longer one Holy Roman Catholic Church, but a multiplicity of avenues in terms of the forms of worship to discover one's own path to salvation and to receive the gift of salvation, not the burdensome chore Christianity had become. So, now we have Baptists, Methodists, Lutherans, Presbyterians, Seventh-Day Adventists, and on and on and on.
But still, Luther's ideas would not have gained traction if it weren't for the printing press. This cannot be overstated. However, if it weren't for a few curious and moneyed Florentine individuals who were interested in antiquity, the Renaissance might not have been bankrolled and the notions of Humanism might be silent in an ancient age or be delayed in coming at a later date. Gutenberg and Luther may not have been the products of their environment that they were and never been given to wild imaginings of invention or be led to rebel against a gigantic system.