A group of commuters on a packed Sydney train have verbally shut down a self-described "anti-abortion preacher".

A video shows the American yelling at a group of travellers, calling on them to "return to living in a moral way".

"We care more about saving the whales, than we care about saving our unborn children," he said.

All you care about is more sin... it's a selfish world that you live in and you need to repent.

It didn't take long for locals to clap back, with two men initially asking the American to "just shut-up".

"Mate if you ask for our time we have the right to say no - we're not giving it to you."

But that did little to stop the "preacher", who claimed his public speaking efforts were because he "loved" his fellow commuters.

Cue a nearly seven minute verbal stoush between the American and primarily, one older Aussie man, who fired back with gems like:

It's great that you care, but I don't want you to tell me this shit.

"Who's the selfish one here mate, who's the one who won't shut up with their opinions - how selfish is that?"

A cutdown of the video can be found above.

The reaction video was uploaded to the "Torch of Christ Ministries" YouTube channel, which describes itself as a group "changing the world one soul at a time by burning the light of Jesus Christ into all the dark places".

It's already racked up over thirty thousand views, but the majority of the comments seem to congratulate the Sydney locals on their verbal take down.