I think about all the reasons which make it the most clear-sighted thing in the world... I also make a Prayer for God to keep making it easy for me, and not to take his holy ghost from me
In addition to prayer and spiritual direction, I sometimes draw comfort from the fact that much more brilliant brains than I are fervent believers eg Chesterton ,Belloc, Lewis , Tolkien to name but a few.
Ultimately I'd stay, you have to ask yourself, is your religion conditioned on mass social approval? Or not! And even if you find yourself sadly admitting that your religion is based on mass approval, think of the countless saints, compared to the ptiful amount of atheists (almost all living today)... I think of that wonderful phrase from Chesterton.. "Tradition means giving a vote to most obscure of all classes, our ancestors. It is the democracy of the dead."
Like others have said, besides prayer, I remember that very bright people do exist who are believers, as well as remembering the love and exceptional forgiveness, grace, charity and mercy that I have seen from Christians that is seldom expressed from non-believers, which makes them unique and proves the spirit is working in them. I am often debating among myself and in my mind the claims or negative things claimed by atheists or anti-Christian radicals, but realize I often do it with a spirit of excessive rationalism and anger, whereas in childlike humility I remember the compassion given to me by the simpler, humbler practicing Christians who didn't rely entirely on arguing to show that the spirit had power. It reminds me that I can't just win this battle purely by my own reason, and reminds me that I need to immerse myself in simple faith and obedience to experience the spirit at its fullest.
I remind myself that Jesus was often plagued with doubt Himself. Christians often forget His prayerful demand in Gethsemane to escape His fate ("Abba Father,...remove this cup from me!") and remember only His ultimate surrender to God's will ("Yet not what I want, but your will be done"--Mark 14:36).. But then on the cross another weak moment: "My God, my God, why have you forsaken me (Mark 15:34, quoting Psalm 22:1)?" Then there is the compelling summation of His human struggles in Hebrews: "In the days of His flesh Jesus offered up prayers and supplications with loud cries and tears...We do not have a high priest who is unable to sympathize with us in our weakness, but we have one who in every respect has been tested just as we are, yet without sin (5:7; 4:15)." Jesus' example tells me that painful doubt can be an essential part of an honest yet passionate spiritual quest.
I have never doubted God's existence. Besides the classic arguments, it is simply illogical (to my mind) to believe that He doesn't exist. My doubts have had more to do with the Christian faith, in particular certain aspects of it. But I do believe that it is a reasonable faith, and while we can't know all the answers to our questions ("For now we see through a glass, darkly; but then face to face: now I know in part; but then shall I know even as also I am known"), I am confident enough in the faith to hold fast to it.
Doubt is a natural concomitant of faith. The desire for certainty is irrefutable evidence of lacking faith. Certainty of unseen and intangible truths is not faith, it is a form of delusion. Certainty is always something that can be 'proved' and only applicable to what can be seen, felt or measured. What is faith? It is the confident assurance that something we want is going to happen. It is the certainty that what we hope for is waiting for us, even though we cannot see it up ahead. Men of God in days of old were famous for their faith. By faith--by believing God--we know that the world and the stars--in fact, all things--were made at God's command; and that they were all made from things that can't be seen. Heb.11:1-3 TLB.