Jesus: "I'm God."
Guy: "No you're not"
Jesus: "Yes I am, watch me bring Lazarus back to life. I'm gonna do this for all of you when the time comes."
Guy: "Ok you're God, and Jupiter is BS."

Roman: "Ok, he brought a dude back to life, but he's not God. Worship Jupiter or I'll feed you to a lion, cook you to death, or something else horrible."

If Jesus really didn't perform a miracle:
Guy: "Ok we were just kidding. Hail Caesar."

If Jesus was legit:
Guy: "No."

Third argument for God: Miracles. I touched on it a bit already. But they still happen. A person who has made up his mind already will never be convinced. But an open minded person, especially with a bit of scientific knowledge, will see. A quick Google search will find you all sorts of people coming back to life when they should have been braindead. I wasn't born yet but it happened in my family and there were several eyewitnesses including non-believers, and doctors said it defied all medical science.

There is also the Congregation for the Causes of Saints, an institution within the Catholic Church that is responsible for investigating miracles today. Things they have investigated were often witnessed by a lot of people. There is a process to recognizing a miracle as legitimate and many are never ruled on because we don't know.

If it were just a BS rubber stamp there would be many more approved miracles, especially without witnesses.

Why do miracles happen to nonbelievers?

That's probably the best person for it. I already believe in God. Showing me a miracle isn't gonna change me.

However showing someone who may not believe or their faith is weak, is a powerful persuasive argument

But it does happen to both. Christians and non-Christians.

The most famous example is probably the conversion of Emperor Constantine.

In 312 AD, prior to the Battle of Milvian Bridge, the emperor saw a cross or chi-rho (☧) in the sky and the words "in hoc signo vinces"

In this sign, conquer

He ordered the chi-rho to be painted on the soldiers' shields, won the battle, and refused to perform the customary pagan sacrifices after the victory.

He then legalized Christianity and returned all confiscated Church property

Why would a pagan emperor who is killing off a minority religion, suddenly convert to that religion, legalize it, and give them all of their stuff back?

This would be like the King of Saudi Arabia suddenly becoming Christian, giving a crapload of land and money to them, and legalizing it

Link me an article that goes in depth with it.

Google is your friend, friend. "Conversion of Emperor Constantine"

Fourth argument for God: the continued church. Religions that were mainstream in some countries a thousand years ago are all but lost to us. We do not know much about Germanic/Saxon/Norse pagan religion except the basic stories and that all three were essentially the same. Same can be said for any other religion, there is so much lost knowledge.

Meanwhile from the time of Christ until today, the Church believes and teaches the exact same thing, using the same scriptures, same prayers, same basic form etc.

Despite the Muslims, pagans, Protestants, and even several corrupt popes, the Church was not extinguished and none of its teaching has been lost.

By itself that is a weaker argument and does not give us supremacy over Jews and Muslims, but at least it does show a miraculous preservation of an institution despite being attacked from all directions and occasionally its own leaders.

Fifth argument for God: Biblical prophets. Isaiah wrote in the 700s BC about the fall of the Babylonian Empire, conquered by a King Cyrus, and some other details, all of which actually came true two centuries later as documented by the Greek historian Herodotus.

There's also a ton of OT writing predicting Jesus and John the Baptist. Not just actions that a person can choose, but things people cannot. Such as family tree, birthplace etc.

Sixth argument for God: Europagans. It is an established historical fact that the pagan Saxons, Germans, and Norse all followed basically the same religion, and things like chattel slavery, human sacrifice, massive infanticide of females, mass war rape, torture, polygamy, and other incredibly strange and horrible stuff was standard practice for them. Their religion was that only a warrior who died in battle would enter Valhalla, their whole society was built on this. Particularly the Norse did not have good land for farming, so they made their living by killing people and taking stuff from them. While a lot of internet dumbasses might say otherwise, it is an established fact that the vast majority of these people converted to Christianity without bloodshed. They abandoned centuries of a religion that actually sustained their needs quite well to adopt one that pretty much banned their only livelihood (raiding) as well as slavery, polygamy, infanticide, and other cornerstones of their society that they actually believed necessary for their survival.

In particular, the miracle of Saint Boniface. Somewhere in modern Hesse, Germany, was a giant sacred tree called Thor's Oak.

Saint Boniface met the pagan militia there, where they were going to sacrifice a child, which was the practice of their religion. This tree was big and indestructible, and if somehow someone were to cut it down, Thor would strike him dead.

So he took an axe and cut that tree down right in front of everyone worshipping it.

According to Christians anyway

A wind came from nowhere and finished the job. Some stories say he cut it down with a single strike.

No lighting or anything. So the pagans converted to Christianity on the spot. Saint Boniface however, was actually sent there and sponsored by none other than Charles Martel. Those soldiers then fought in his army against the Muslims invading through Spain, at the Battle of Tours.

I wholeheartedly believe it happened. But, to be the devil's advocate...whatever the real truth might be, we do know that the Frisian pagans killed Saint Boniface for what he did to the tree.

Charles went on to win a miraculous victory against a numerically superior force including cavalry, with his own force consisting mostly of heavy infantry, taking relatively few casualties and even killing the Muslim governor of Spain.

His grandson was Holy Roman Emperor Charlemagne

We still find mass graves from the Roman era etc. But we aren't finding that from the Europagans. There's no hard evidence they were converted by the sword, so why would they all give up their ancestral religions and adopt a "foreign" faith? My answer, though you probably won't accept it, is miracles. To be a saint, someone must have miracles attributed to them. Saint Boniface, Saint Patrick, and so on. Did they perform miracles in front of the masses of pagans, as proof of God?

Fast forward a couple more centuries. The Crusades. Why Islam is illegitimate is another topic I can prove beyond a reasonable doubt. So we know what they did, they basically killed everyone. But it is basic Islamic theology that any Jew or Christian who volunteers to convert to Islam is spared. This hasn't changed in 1400 years. Of course they don't always honor this, but why the MASSIVE slaughter in the Holy Land, unless people refused to give up their faith? Some Jews survived, that's about it.

Under feudalism all fit male commoners must serve in the army of their lord for 40 days per year, but cannot be deployed outside of their lord's territories. Hence the need for mercenaries. Knights owed service as well, but also had to work as a kind of frontier police, judge, and do other things. The key here is that everyone who went on "pilgrimage" as it was called back then, was a volunteer. They had to buy their own weapons, armor, everything. Imagine you are going to fight ISIS, but you must buy your own tank, your own food, ammo, transportation, everything, and you will never be reimbursed, never get paid for it, and will probably die.

Pilgrimage prior to the Crusades was religious tourism, and people who went to holy sites, such as the sites of the birth and crucifixion of Christ, etc prayed for things and actually believed that miracles would happen from doing this.

They didn't stop because of the Muslims. They just ended up getting killed a lot.

Why would people go through all this, multiple times even, unless there was something to it?

If I eat something that tastes like shit, I don't eat it again.