Nothing but God
If God is Unconditional Everlasting Love, everything that happens is coming with & from This Love. Even the painful stuff.
Why would God allow suffering if God loves us?
Because on the other side of the suffering is a Light & a Love that we can only tap into through experiencing its opposite first.
Because this life is veiled by the illusion of duality, we must experience pain to be alerted to the Love that is awaiting us. If we never experience the pain, we would never seek God's Love.
This is the human condition :: we find Oneness by experiencing duality.
Because the universe is Unity expressed through multiplicity & we are the universe.