Many Christians, and I am one of those; who believe that God knows everything, controls everything, and is everywhere simultaneously. This idea is commonly known as God being omniscient, omnipotent, and Omnipresent. To most of us that simply means that God is with his people at all times, that God knows everything and every circumstance that will take place right up until the end of time; and that he directs circumstances in order that things will happen exactly the way he wants them to right up until the end of days.
There are innumerable concepts as to how much control God uses to accomplish his goals. They range from superficial management, all the way to micro management.
Those who are prone to believe that God micro manages base that belief on:
Matthew 10:29 through 31 NKJV Are not two sparrows sold for a copper coin? And not one of them falls to the ground apart from your Father's will. 30 But the very hairs of your head are all numbered. 31 Do not fear therefore; you are of more value than many sparrows.
However; to think that God micro manages everything, every incident, and all events; would appear to my simple mind to take away a free will.
There are however; some incidents in which it would appear that only holy intervention could have caused some result.
To this end I will cite this incident.
I have a close friend, who was diagnosed with terminal cancer. He was given only a few months of life by several doctors. After many prayer sessions, by both he and others in the church; he returned to the doctor who originally diagnosed him with the cancer. On that visit there was no sign of cancer left, and today 10 years later he is still praising God for that healing.
Although I cannot say that I know beyond a doubt that his healing was God's work, I do believe that there is no other explanation.
Christianity, is known as faith for a reason;
Faith according to Merriam Webster; is. Latin: to trust; Greek: to persuade, to draw towards any thing, to conciliate; to believe, to obey. Belief; the assent of the mind to the truth of what is declared by another, resting on his authority and veracity, without other evidence; the judgment that what another states or testifies is the truth.
I have abbreviated this definition because it was extremely long; however; it still contains the main idea which I want to convey. That idea is that faith and free will are almost the same thing as far as Christians are concerned. One can either choose to believe or not believe. Just as one can choose to believe or not believe things that are written in the history books are other similar publications. And the depth of that belief can have a wide range.
Hope this helps.