We live in this world like a child who enters a room where a clever person is speaking. The child did not hear the beginning of the speech, and he leaves before the end; and there are certain things which he hears but does not understand. In the same way, the great speech of God started many, many centuries before we started learning, and it will continue for many centuries after we turn to dust. We hear only part of it, and we do not understand the biggest part of what we hear, but nevertheless, a bit vaguely, we understand something great, something important. If you truly love goodness (God), then you cannot have doubts in your immortality.