I think the spread of Christianity was unintentional and much of Rome's technology came from the ancient Greeks.
Rome's Technology came from the Greeks? I would grant that the basic mathematics, algebra, and calculus may have come from the Greeks, but it was the Roman Engineers that applied them to real world problems and tamed the natural world. I never heard of any 60 mile GREEK aqueducts.
I recently learned from a documentary though that the Romans didn't have the calculus skills to survey bends in their roads, so they went straight as an arrow and then turned 90 degrees, and still do on the old Roman Roads in England and elsewhere.
Unintentional from the Romans' point of view.
Lions 1, Christians 0
But I think that both Christ (remember Constantine) and the Christians very much intended Christianity to spread.
Cheers!