[Jon Francis (OP)]

Will a light beam continue travelling forever or will it eventually fade.

[Soul Surfer]

As long as they are not absorbed the individual photons will continue travelling for ever but they will become further apart so the intensity of a light beam fades.  however on the scale of the whole universe the expansion of space must be taken into account and this stretches them out and creates the red shift which causes them to loose energy when observed from a distance but from the point of view of the photon nothing has changed.