Faith is the cornerstone of all monotheistic faiths, it's what you need to believe because there's no shred of actual evidence for the supernatural.
Faith is supposed to exist and in a quantifiable manner since as Jesus said:
Ye of litle faith
And the quote of how faith the size of a mustard seed could move a mountain, assume Jesus meant this literally since the bible isn't short on miracles that defy logic like a global flood, giants among others.
If you entertain like Moses could do improbable things like split a river which if you think of it from a Sci-Fi perspective sounds like some form of telekenisis. If the amount of faith you have and the graces of God determine how likely you are to perform miracles as churches do still claim that this is the only requirement as is with modern day healers and miracle workers.
To put this to the test:
He replied, "Because you have so little faith. Truly I tell you, if you have faith as small as a mustard seed, you can say to this mountain, 'Move from here to there,' and it will move. Nothing will be impossible for you." - Matthew 17:20
There's only two ways around this, either this was meant figuratively or literally. If not literally then for such a direct claim it's a false claim and can as well prove the lack of power in the almighty, since there's another verse on how in the name of Jesus if a venomous snake bites you, you'll not die from the poison.
Some "fanatics" have tried to prove this by getting bitten with full faith Jesus would heal then and it didn't end well for them.
But if it's literal consider this:
No one can or has moved a mountain, no one has actually showed any telekenetic powers so to scale this, to move a mountain in an acceptable easily noticable distance it would likely not be less than 1km. But for simplicity sake not asking the believer to best magnito or some other X-Men character, all you have to do is move a pea through the distance of a pea.
If you consider the shrinking scale of how much faith you'd need to move a mountain, the size of a very small seed
Mustard seed to scale
And how much to scale to move a really smaller item, a pea, ignoring the fact the mountain would have to also be uprooted first the scale of faith you'd need to move one pea just an inch is practically non-existent. The amount of faith you'd need to scale would be about the size of an atom if not smaller.
This leads to one of two conclusions, either the source of the power, God isn't real or you're faith isn't real, it isn't there. Of course you have faith because you faithfully go to church and do believe God exists, so it must mean then God isn't real, if you prefer either his power had dimished greatly, he ceased to exist or never existed. Or he broke of the contract with humans but that's an easy escape that's a zero-sum game where you get to believe in God but every verifiable, falsifiable claim can be ignored also due to unforseen circumstances.
If you consider how churches today are making a killing convincing you this preacher is better than that one because he can tap into the heavenly power more than the other, evident by his ability to perform these miracles which aren't as prominent on this other church, I have to wonder why people still do believe that there's actual healing going on in church.
For starters, you never do really give tithe to God; nothing you give goes to your creator, and to assume the creator of the universe if you can comprehend how vast and awe-filled it is needs your money however little it is relative to the entire amount of money on earth as proof of your devotion to him, so that he will return it back to you 10 fold, or in some other way be it healing your ailment, some string of lucky events or what-have-you that's the opposite of chasing the leprechaun, where you give money so you can chase the rainbow, if you believe that money isn't what makes preachers very wealthy, that's what has made the catholic church the richest religion and if christianity didn't fracture the amount of wealth it would have would be unfathomable, if they would ever allow us the freedom to do as we wish. Christian religions have to be the richest organisation that collect money from people for an unambigious service.
But still to the point, what it might take to actually prove to the scientific community and the non-belivers as a whole that God is real would be a simple test. Before I tell you how this test supposedly went because I'm not sure if it was ever conducted you, if you're religious might retort that God isn't to be tested, that's how it should work blessed are those who believe without faith. As I believe some quote goes in the bible, but remember in the Old Testament God never shied away from doing feats of magic to prove he is real; that's what Moses tried to do proving to the Pharaoh even though as a verse prior to this God somehow made him hard of head which makes you wonder why he would make you stubborn and send someone to convince you, which side he's routing for, like he's itching for a reason to justify his actions. The story of proof which God is real by placing sacrifice on altars of meat and asking each God to try and burn the sacrifice as sufficient evidence and God won. If you think about it, miracles stopped being valid once the camera was invented, same as a lot of other myths.
This is a simple test and unlike asking someone who suffers from a serious disease to wait for a miracle and risk their health, this would put the person in mind at little risk.
The test would be to cure someone of the common cold, this person can be tested to have the cold with a simple blood test and under supervised lab conditions the preacher or healer would be free to pray and chant all they want then when they feel the healing is done another test can be done to confirm the person has or hasn't been cured. Since it's doable to know how developed along the cold is and estimate how long it might last without medication the healer would have to only perform the miracle between this time line.
A cold can last for a week or more, and if the healer can't cure you of a cold in a week but needs more time, this would be proof of both lack of power and/or incopetence from his/her source of mystical power.
As the story goes bold preachers tried to prove their church is the one true faith and all failed this test till no one dared to take it. In the face of proving to science God is real and I believe also win a prize if you can perform a miracle still no one would dare risk their reputation on this.
The point here is we have little faith that God exist, but the humor is really among his congregation we can spot plenty, probably the majority of ye with little faith that men can defy logic and perform real miracles.