The Licht.von.Finsternis is a proselytizing, infected Rheinlander called Benedikt Emmerich in his battered old military ship. He preaches about the Light, and tries to get people involved with the Light and love and unity. Mainly he reads out of a tome I make up as I go along with a generic myth about the first hybrid, and his desire to bring all the humans into a state of unity via hybridization. Much of the tone is from the Lutherian bible, and the name Licht von Finsternis is from the part of Genesis where God brings "Light from Darkness".
I say "his", because I tossed a coin and it came up tails.
So there's one religious character.
Pato Dooley and Mag Folan are both Mollies, and are both god-fearing. The whole Molly=IRA point of view forgets, purposefully or not, that the IRA are a minority in Ireland. There are sympathisers, certainly, but not everyone in Ireland goes around planting bombs and shooting policemen. Same with the Mollies. As to Mollies not being Irish because they were Bretonian... In our history, the Irish were British by dint of the British Empire. Then they broke away (which was a long and drawn out affair with much political affray and civil unrest).
With regard to the claim that religion is not in Freelancer, we in the Current Era are constantly reviving old religions or borrowing them from other cultures. Why would that not be the case in Sirius? Colonists would bring their religions with them and practise, or simply remember the old days/past generations.
If the citizens of Sirius were ever to forget the fervour of faith, the SCRA would remind them of fanaticism in their worship of the Cult of Communism.