VOYAGE
The physicist best friend of an Illinois construction worker offers to help save his terminally ill son's life by taking the grief-stricken father back through time to retrieve what he believes will heal the child — the blood of Christ.

The 'physicist best friend', 'Construction Worker' etc., reads a bit convoluted. Also, do we need to know he's from Illinois?

I'd try simplifying it.

In a desperate bid to save his terminally ill child, a man calls upon his best friend, a particle physicist, to help him travel back in time to retrieve the only cure that will save his son's life - the blood of Christ.

A man calls upon his friend, an astrophysicist, to help him travel back in time in a quest to find the only cure that will save his terminally ill son - the blood of Christ.

Still a bit of a mouthful...

P.S. Wow, that's some inclusion with 'the blood of Christ'.

What LC said! I tried reading your logline out loud and quickly became out of breath. It's a great tongue twister though! Kidding aside... intriguing concept, maybe do more alluding-to rather than spelling things out literally. Good luck!