How interesting it is that almost everybody who believes in Hashem has a battle maintaining and strengthening the belief. If one is not constantly working at it then chances are that the belief is weak. R' Yechezkel Levenstein ztz"l said that he worked for decades on his Emunah and yet if one day passes where he doesn't work on it he feels it floundering.
However, atheists rarely if ever have struggles maintaining their atheism. You won't meet an atheist who is deeply troubled and depressed. When you inquire as to the source of his distress, he tells you "I am having SERIOUS DOUBTS. Maybe life DOES have meaning. Maybe the incredibly mind blowingly complex universe did NOT create itself. [Study JUST the human eye. That is enough to be CONVINCED that there is a Higher Intelligence involved here]. Maybe there IS a Kind, Loving G-d up there with whom we spend bliss for eternity and we don't just die and get eaten by worms and that is the end of us. Maybe the evil WILL be punished for their terrible deeds and the righteous WILL be rewarded. I don't know what to do with myself. This is SO distressing."
You don't hear it. I heard one world renowned speaker say that when he addresses atheist crowds and asks how many have doubts about their belief [in nothing...], [almost] no hands go up. While believers often have their doubts or times of weakness.
The explanation - what is easy is usually not worth much. Important things come after HARD WORK. ותרא כי מתאמצת היא ללכת ותחדל לדבר אליה. When Naomi saw that Rus was expending so much energy to remain with her and to convert - she stopped trying to dissuade her. She knew it was true and sincere.
To be a Kofer is NO WORK. All you have to do is whatever you feel like whenever you feel like it. From מאמין to כופר entails having to think, hear, see, say and do [or not think, hear, see, say and do] a million things a day to thinking, hearing, seeing, seeing, saying and doing whatever one wants. From כופר to מאמין entails going in the opposite direction - from zero obligations to millions.
To be a מאמין is hard because it is real, true and the purpose of life. To be a Kofer is easy because it is meaningless and the opposite of why we are here.
Mussar Haskel: Hard is good. Exercise, diet, religious belief, middos tovos, learning Torah. All challenging but well worth the effort.
Easy isn't good. Watching movies and znus, daydreaming, overeating, being lazy, spending ENDLESS hours on line etc. etc.
