A non-Catholic friend that I have known for over 50 years said to me recently, “How I envy you your certainty!” By that I took him to mean that he wishes he could believe what Catholics believe, but feels he cannot. I was tempted to reply, “Try harder!” but in the circumstances I kept quiet.
Nevertheless, while believing is an act of the mind and not of the will, if the human mind is to believe the supernatural truths of the Faith which are intrinsically above its natural reach, the mind does need to be pushed by the will. Therefore while supernatural believing is not an act of the will, it is not possible without an act of the will. “Nobody believes against his will,” says St Augustine. That is why to “try harder” with the will, as advice for somebody whose mind does not believe, is not as unreasonable as it may seem to be. Nor, if the beliefs towards which the will is pushing are objectively true, will that advice, as such, result in wishful thinking.
Firstly however, if a man really and truly envies the certainty of Catholic believers, he should apply his mind to studying how reasonable are Catholic beliefs. They may be above human reason, but they are not against it. How could they be? How could God both be the creator of our human reason and then impose on it to believe truths flouting that reason? He would be contradicting himself. St Thomas Aquinas in his “Summa Theologiae” is constantly showing how faith and reason are quite distinct, but in perfect harmony with one another.
Then what human reason can do, and what my friend should do, is to build a natural ramp towards the supernatural Faith by studying for instance the entirely reasonable arguments that prove the existence of God, the divinity of the man Jesus Christ, and his divine instituting of the Roman Catholic Church. These arguments are well within the grasp of natural reason, as long as the will is not pushing against, because the mind misapplied will never recognize the truth in front of it. The will must want reality, otherwise the mind will never find the truth. Truth for us men lies in the conformity of our minds to reality.
Once a man has done all he can with right reason and upright will to grasp the reasonableness of the Faith, he still does not have the supernatural faith, which remains a gift of God. However, how can God require of us to believe (on pain of eternal damnation – Mk.XVI, 16), and yet refuse the gift of faith to a soul which has done all within its natural powers – but God is not deceived – to prepare itself for that gift? Especially if, as is reasonable, after doing what I can, I then humbly ask him for the gift in prayer? He resists the proud but he gives his gifts to the humble (James IV, 6), and he lets himself be found by those who seek him with an upright heart (Deut.IV, 29; Jer.XXIX, 13; Lam.III, 25, and many other quotes from the Old Testament).
Dear friend, read and ask. The certainty is most likely yours for the trying.