J
The problem does not lie with God here but with your attempt to hold God accountable to a humanly derived standard of ethics and fairness. If there is one thing that scripture teaches us it is the fact that God is VERY selective but never unfair. His choosing of one above another is seen many times in scripture. "Or does not the potter have a right over the clay, to make from the same lump one vessel for honorable use and another for common use?" Rom 9:21. You are also assuming that the healing itself is somehow of significance, It is not. He is also at times vengeful but this does not make him cruel.