not sure about the "randomly" bit, and really more concerned with what the scripture says, not what any human makes of it..
What shall we say then? Is there injustice on God's part? By no means!
For he says to Moses, “I will have mercy on whom I have mercy, and I will have compassion on whom I have compassion.”
So then it depends not on human will or exertion, but on God, who has mercy.
(Romans 9:14-16)
if God has chosen to show mercy to some and not to others, what is it to you?
how shall we respond?
shall we judge God? or shall we continually seek His mercy and rejoice that we have found it?
the command is to give thanks in everything, so how can i thank God that i was wise enough to choose Him? i will thank Him that He put it in me to be able to do so, because apart from Him, no wisdom is in me. then the glory is His alone!