Love of goodness and faith in immortality are inseparable.
Nobody can say that he knows what the afterlife will be. Our beliefs are based not on logical proofs but on moral ones and therefore I cannot say that God exists and I am immortal, but I can say that God exists and that my "self" is immortal. This means that my faith in God is so closely connected with my nature that this faith cannot be separated from me.
— Immanuel Kant
The animal beginning disappears, the veil is taken from the future, the darkness disperses. It is then that we feel our immortality.
— After Saint Martin
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.