He also said that Christians cannot explain why suffering exists in the world but that the answer was faith
It looks like someone wasn't catechized very well...
Actually, there is no answer to the question of evil, even in Christianity. As per the book of Job, God's answer is basically "This regards the very foundations of how reality is, because you are a piece of that whole, you'll never be able to understand. What you want is peace of heart and that you will get by moving on from this question and remembering that I am good, loving, merciful and I will have the last say"
That is echoed by Elder Paisios when he says "What I see around me would drive me insane if I did not know that no matter what happens, God will have the last word.”
My own take on that is that question "Why evil and suffering?" is wrong in itself. Real evil and real suffering are so precisely because they lack meaning, so to ask why about something that is fundamentally an absence of "whys" is nonsensical in itself.
We do have partial answers though, specially in the temptations of Christ.
Why don't you use your omnipotent power to fulfill man's material needs? Because man is not to live on bread alone.
Why God don't you make yourself obvious? God can't be "seen" by being tested, implying that even if He did something like being perpetually visible on His throne floating in the skies, people still wouldn't believe in Him the right way.
Why God, don't you just solve all the problems by force of coercion? Because by doing that God Himself would be acknowledging brute force as more powerful than Himself which it is not.
Then, in the Sermon of the Mount, He teaches us the right way to achieve all that the devil tempted him to:
Blessed the meek: for they will inherit the earth.
Blessed the pure in heart: for they will see God.
Blessed those who are persecuted for righteousness' sake: for theirs is the kingdom of heaven.
That which the devil offers through brute strength: material fulfillment, vision of God and control of the world can only be obtained through meekness, purety and martyrdom.