The most persistent and pervasive myth is that family history work is for the retired old folks in the Church. If all the people who have told me they are waiting for retirement to "work on their family history" actually did so, the percentage of people contributing names to the Temple for ordinance work would increase dramatically. The truth is that retirement does not free up time for things that are not a priority. If family history work is not a priority in your life before you "retire" then it will have a low priority after retirement. The fact that old people retire from active work is one of the most dominantly pervasive myths of our whole culture. For me, retirement from one job merely meant I had time for another, even more full-time, job, that is, genealogy.
It is hard to rank myths in their degree of pervasiveness, but one right up there near the top has to be the myth that family history is something separate from and different than the other activities of the Church. Quoting from a talk given by Elder David A. Bednar in a Seminar for New Mission Presidents on June 25, 2013:
Missionary work and family history and temple work are complementary and interrelated aspects of one great work, “that in the dispensation of the fulness of times he might gather together in one all things in Christ, both which are in heaven, and which are on earth; even in him” (Ephesians 1:10).So, Temple and Family History work, along with Missionary work are all the same great work. If we separate and compartmentalize family history as a "separate work," we are buying into the myth.
Yet another myth is that family history is somehow just another program of the Church and that you need to be "called" to do family history like you would be called to any other calling in the Church. Quoting from the Teachings of Presidents of the Church: Joseph Smith (2007) at page 475:
The greatest responsibility in this world that God has laid upon us is to seek after our dead. The apostle says, ‘They without us cannot be made perfect’ [see Hebrews 11:40]; for it is necessary that the sealing power should be in our hands to seal our children and our dead for the fulness of the dispensation of times—a dispensation to meet the promises made by Jesus Christ before the foundation of the world for the salvation of man.This is an individual responsibility, the call comes with your acceptance of the Gospel of Jesus Christ. No one needs a special calling to do family history work for their own ancestors and cousins.
There is a persistent myth among some of the members of the Church that their family history work is all done. This is usually attributed to some relative that did a "lot of family history work." I have members tell me this regularly. Usually, this is in conjunction with a mention of family history work that I initiate. Simply put, this is virtually impossible. I have a standing challenge that I have been making for years, that is, that if you give me ten or fifteen minutes with your pedigree on FamilySearch Family Tree, I can find issues that will show you that the work is far from all done.
Myths continue on. It seems like the community makes up new ones despite the fact that they have a surfeit of myths already. It is common for people to claim that they don't have to do any family history because it will all be done in the "Millennium" anyway. It is a serious mistake to believe that anyone can shirk their duty by simply passing the duty on to someone in the future without suffering the consequences of their actions. At the very least, those who forego doing their family history merely because it will all be done by someone else at some time in the future will forfeit the blessings they could have received for doing the work themselves. Here is what LDS.org has to say on the subject:
During the Millennium, all people on the earth will be good and just, but many will not have received the fulness of the gospel. Consequently, members of the Church will participate in missionary work.
Members of the Church will also participate in temple work during the Millennium. The Saints will continue to build temples and receive ordinances in behalf of their kindred dead. Guided by revelation, they will prepare records of their ancestors all the way back to Adam and Eve.There is obviously some work that cannot be done at this time, simply because the records are missing. But I seriously doubt that anyone in the Church can so easily divest themselves of their sacred responsibility to assist in the work of redeeming their own kindred dead.
If am sure that these myths will continue to propagate through the Church. But it is my hope that by educating and teaching, their impact will become lessened.