A: The truth is that the vast majority of people will probably go to heaven. The Urantia Book teaches that survival after death is gained by faith—just the kind of faith you asked about in your first question...but even the faintest flicker of faith is sufficient to propel us into eternal life .The only thing that will prevent anyone from moving forward in the Father's ascension plan is the deliberate and willing rejection of this plan of survival, or a deliberate and consistent embracing of sin.
On a planet such as ours—isolated from celestial circuits, darkened by rebellion and sin, marred by the partial failures of epochal revelation—faith is the great challenge. Even to those who have no knowledge of the heavenly Father, faith can come—even a simple faith that there must be more to come after death will probably be sufficient to ensure survival. Once we experience that survival and waken on the Father's "many mansions ," we will have ample opportunity to make the final choice for eternal survival.
Here in this earthly life, so many of us lack the basic understanding of who we are, where we came from and where we are going. It is very easy to falter and fall by the wayside as we grope in the darkness, but God understands. All of us come up short when it comes to being "perfect, as the Father is perfect." He knows what kinds of challenges we face here, and he does forgive our shortcomings. He is not willing that any should perish.