Faith is so much part of Christian life that it is sometimes used as a noun rather than a verb. As a people we believe, and at just about every one of of principal liturgies contains a statement of belief.
Usually this will be one of the three ancient creeds of the Church, The Apostles Creed, or the slightly longer Nicene Creed. These are the two you are most like to encounter. The Athanasian Creed is very much longer, and very rarely used in public worship these days. The reason why the Church had councils that settled on agreed statements of belief is because there was a desire to agree on the fundamentals. There is no doubt a range of opinion about the creeds, however we hold them as of great value in keeping us on track.
In essence all the creeds point to a belief in God understood in terms of Trinity. The Creator - above and beyond all, The Redeemer - Jesus the Son as God incarnate, crucified and Risen from the dead, The Sanctifier - as near as breathing guiding and directing us. They also acknowledge the role of the Church, the importance of baptism, forgiveness, and the hope of us all found in the resurrection.
Faith of course is different to science as we know it today, yet for us as Christian believers we would say that faith goes beyond where reason takes us, not against where reason take us. And in practical reality for most of us there are moments when we doubt, not a bad thing, simply something that points us to the reality of faith rather than science.
As the Parish of Cardiff we delight that our Parish Church is named for St Thomas, who was the apostle not with the others when Jesus first appeared, and for a great deal of struggle Thomas said he would not believe, and when he did, he then strongly proclaimed 'My Lord and My God'.