I have read the word used in the Bible for the duration of hell is in fact a finite but large number. Hell is not, even on the Biblical rendering, forever but a very, very long time.
Be all this as it may, I don’t think the fear of Hell motivates bad people very much to change their ways, and where people who might be good are concerned, I think it creates a terror that leads to a permanent limitation in their capacity to see, and the capacity to see is, alone, the sole reliable path into higher spiritual realms. The idea of hell stunts most people, and I think a focus on it makes them mean.
The path forward is through reasonable enjoyment. Through learning to appreciate life’s beauty, the companionship of others, music, song, dance, through creation. You need the smallest amount of anxiety to start things, but once you are on the river, growth will happen if you pursue “autotelic” experience, which challenges you but does not scare you too much.
All this, though, within a framework like Buddhist, or even Spiritualism, which posits spiritual growth as a possibility, and places this life in a larger context.