Preachers, medical doctors, and lawyers are all highly respected professions, which as a requirement demand from its disciples: diligence, studious effort, persistence, intelligence, post-secondary education, and desire. These esteemed professionals are certainly worthy of our respect and appreciation because we need a good preacher for the good and training of our soul, we need a good medical doctor for our birth and to maintain good health, and we need a good lawyer for the trials and tribulations that living in this complicated world will invariably bring to our door.
However, there is another way of looking at these professions, no matter how noble, and how appreciative we are of them and that is, that these professions are all somewhat dependent or very dependent upon the foibles of human nature. That is to say, the preacher needs sinners, as isn't this what Jesus the Christ preached about when he said that: "I came not to call the righteous, but sinners to repentance" (Luke 5:32). So too medical doctors depend upon sickness and illness that will bring to them a multitude of patients that will need healing or amelioration on these things. Then, there are lawyers, who are dependent upon each man's nature to want his own way, regardless and even to the point of cutting off his nose to spite his own face.
It's good to look at things from time-to-time from a different perspective and a different prism, because really if you think about it carefully, if man was so good, he would have no further need for instruction, prophets, or a savior, and the fact that mankind does indeed need these things, reflects that we are not as good as we might wish or believe. If we all ate healthy foods, exercised, got our proper rest, practiced proper hygiene, and basically carried ourselves in a manner that treated the body and mind as things that needed proper attention and tending to, there would be far more healthier bodies and subsequently far less illnesses. Then too, if we were better listeners rather than talkers, more concerned with building bridges rather than sowing hatred and strife, there would be far fewer disputes, with far less rancor and far less bitterness than we presently experience, and hence less of a need for lawyers to mediate or to champion such things.
It's a bit amusing or perhaps disturbing, to recognize that preachers need sinners, doctors need sickness, and lawyers need quarrels in order for them to be successful in their respective professions, signifying that even these professions, highly respected and valued, are at least in some respect, parasitic, in the sense that they make their profit off of the errors and shortcomings of man's ways, so that if there was to become some sort of heaven on earth, these professions, would be significantly impacted, for there isn't a compelling need for the preacher to preach to the choir, nor for a doctor to spend much time or attention to the healthy, or for the lawyer to do much of anything if each party treated the other with respect and fairness.
Think about this: goodness matters, decisions matters, and our choices matter, so that in heaven, there isn't any need for a preacher, because we are one already with God, so too there isn't any need for a doctor, because our soul is now forever free of error, illness, and darkness, and we certainly don't have a need for any lawyers, because our heart now epitomizes pure justice and truth.