Why does a person need to believe in God?
God is all-good, all-knowing, all-satisfied, and omnipresent, so it is not so much that He needs our faith, but rather that we ourselves need to believe and trust in Him in order to partake in His holiness and love. However, in any case, it is a mutual process. We love God, and He loves us. When we lose faith and love for God, then our heart, as Blessed Augustine says in his «Confessions», is restless and cannot find peace, and we suffer from sins and passions. Only when we restore our connection with Him through prayer and participation in the Sacraments of Confession and Communion do we not only find peace but also gain such peace in our soul that it is transmitted to everyone around us. This is what St. Seraphim of Sarov speaks of: «Acquire a peaceful spirit, and thousands around you will be saved».
Our posthumous fate depends on the degree of our faith and the acquisition of peace in our soul. Evil, passionate people, if they do not repent, are unlikely to count on bliss in the Kingdom of Heaven. They will find it, to put it mildly, uncomfortable there. This is well depicted in C.S. Lewis's work «The Great Divorce». The inhabitants of hell, when they were given a «tour» of heaven, could not stay there long because they found no one akin to them in spirit. As St. Isaac the Syrian reasons, God is good because He created the fiery Gehenna. That is, in Gehenna, people who already in this life create hell for themselves and others will find what they have always, willingly or unwillingly, strived for.
However, even in this life, unbelievers, despite all the entertainment and comfort they try to arrange for themselves, often remain in torment and fear. Because they do not want to realize what every person is called to do – to become like God in love, mercy, meekness, humility, chastity, and many other virtues.
I remember how in the early 1990s our academic choir was received in Paris. The locals perceived us as angels because we believed and glorified God with our hymns. And they, as could be understood from their conversations and way of life (we lived not in a hotel but in their homes), had most likely forgotten about this faith. Therefore, despite their rather comfortable life, they suffered spiritually and longed for consolation from us.
