If you trust God no matter how he acts, then you are in an abusive relationship. The issue isn't whether God could have good reasons for allowing suffering. Serial killers have reasons that satisfy themselves. The issue is whether he could have included less suffering in the world. If he could have and just didn't, then he is sadistic.
If we say God loves humanity no matter how he treats us, then love means nothing. If we can't judge God to be evil, then we can't judge him to be good, either. LINK.