You've suffered more (maybe)... so what?
Since when does the magnitude of a person's individual suffering alter the validity of their argument? The measuring scale game has no worth nor does it garner interest from the objective.
When this kind of statement is made, huge emotionally-driven assumptions are being made. A) That belief in God is "easy" and B) that the person making the statement knows how much suffering the other person, on the receiving end, has endured. It also implies a rather gross pre-conception of the god in question.
Belief has its appeal.
If one conducted a survey, they will likely find that, historically, people have been drawn to faith both from a life of relative ease and of cruelty. For an example of the latter (just to dismantle some of the assumptions made in the entitled statement), the Black Church in the south. Or the crucified apostles of Jesus. Or Jesus.
Perhaps, for these people, belief is grounded less on emotion. The whole 'solid rock' v. 'sinking sand' thing.