You are giving very little information as to what you mean?
from the simple explanation you give I think you are on about the amount of lives
one life being only this life
two lives being earth and heaven or hell
and the three lives being the rebirth or reincarnation model
but still not sure what you re referencing to unless it is one of the levels of enlightenment stream entry being no more than 7 lives etc
He who knows only his own side of the case knows little of that. His reasons may be good, and no one may have been able to refute them.
But if he is equally unable to refute the reasons on the opposite side, if he does not so much as know what they are, he has no ground for preferring either opinion …
He must be able to hear them from persons who actually believe them … he must know them in their most plausible and persuasive form.