The aspect of the human condition that best characterizes Friar Laurence is human nature. Human nature defines our imperfections, our ability to mess up (Collins English Dictionary). Shakespeare demonstrates through characterization that it is due to Friar Laurence's human nature that Friar Laurence develops into a poor father figure for Romeo, making him partially responsible for Romeo's and Juliet's deaths.
Friar Laurence is characterized as having good intentions in mind when he agrees to marry Romeo and Juliet; however, his good intentions are thwarted by faulty human reasoning. Friar Laurence's good intention in agreeing to marry them is that he believes it will help end their families' feud, as we see in his lines, "For this alliance may so happy prove / To turn your household's rancour to pure love" (II.iii.94-95). His good intentions prove that he is characterized as acting as a father figure, not just towards Romeo, but towards the whole city of Verona as well. His good intentions are the reasons why Prince Escalus chooses not to place full blame on Friar Laurence at the end of the play, saying, "We still have known thee for a holy man" (V.iii.281). However, the element of secrecy and deception in which Friar Laurence agrees to carry out the marriage increased the amount of problems for the characters, culminating in Romeo's and Juliet's deaths. Had Friar Laurence convinced Romeo to postpone their marriage until they could at least let their intentions be made publicly known, a lot of deaths might have been spared. Hence the element of human nature that Friar Laurence demonstrates is faulty reasoning, which characterizes him, at least for that moment in time, as a failed father figure.
Friar Laurence is also characterized as marrying the couple while believing that the marriage is rash but, again, does it to put an end to the hatred and violence drenching the streets of Verona. We know that Friar Laurence thinks the marriage is rash, because, like a wise father figure, he accuses Romeo of being too young to truly know what love is, saying, "Young men's love then lies / Not truly in their hearts, but in their eyes" (II.iii.68-69). We also know he thinks the marriage is rash because we see him warn, like a father figure, "These violent delights have violent ends / And in their triumph die, like fire and powder" (II.vi.9-10). Hence, Friar Laurence agrees to marry them because he hopes the marriage will improve the spiritual state of his congregation, even though he does not fully believe that the marriage is a wise idea, which is the epitome of faulty human reasoning, showing us that Shakespeare characterizes Friar Laurence as a failed father figure.
Hence, we see that like all human beings, Friar Laurence's human condition is governed by human nature. His human nature leads him to make some poor decisions, even though they are well intended.