The interventions of God in human history are not always easy of comprehension. For example, in spite of much opposition the Catholic Church has grown through the years. Of course, we most certainly ascribe that to God’s omnipotent providence. The important point is that the Catholic Church simply endeavors to follow its Founder in being faithful to the truth taught by our Lord Jesus and live in accord with the way He lived, as shown by His example. It’s not always easy to understand God’s ways since it’s part of our faith to accept unquestionably what His infallible word tells us.
What is important is our assurance of being in possession of the truth, even if it comes through the Church. But there are signs that are convincing enough. “Go out to the whole world; proclaim the Good News to all creation. He who believes and is baptized will be saved; he who does not believe will be condemned. These are the signs that will be associated with believers: in my name they will cast out devils; they will have the gift of tongues; they will pick up snakes in their hands, and be unharmed should they drink deadly poison; they will lay their hands on the sick, who will recover…And so the Lord Jesus, after he had spoken to them, was taken up into heaven: there at the right hand of God he took his place, while they, going out, preached everywhere, the Lord working with them and confirming the word by the signs that accompanied it” (Mk. 16:16-20).
Much of these signs and miracles have been carefully documented or recorded, if you really care or desire to know about them, more so especially in the lives of the saints, since these extraordinary signs or miracles are a requisite proof of God’s intervention or approval, specially in cases of the canonization of saints.