If he judges a person as worthy of saving, he will save them. God knows us very intimately, he sees into our hearts and he draws us if we have a heart that can be drawn.
Jesus says at John 6:44 No man can come to me unless the Father, who sent me, draws him
Romans 9:14 What shall we say, then? Is there injustice with God? Never may that become so! 15 For he says to Moses: “I will have mercy upon whomever I do have mercy, and I will show compassion to whomever I do show compassion.” 16 So, then, it depends, not upon the one wishing nor upon the one running, but upon God, who has mercy.
But not everyone has a heart worthy of God. Pharaoh was an example of one of those who's heart was not right.
17 For the Scripture says to Phar′aoh: “For this very cause I have let you remain, that in connection with you I may show my power, and that my name may be declared in all the earth.” 18 So, then, upon whom he wishes he has mercy, but whom he wishes he lets become obstinate
Your statement "If he judges a person as worthy of saving, he will save them..." is actually disproved by the verses you cite and your statement is false in this manner:
The common verse between them is from the OT, "I [The Lord] will have mercy on whomever I will have mercy..." In both instances, MERCY being the topic in question, I must ask the question, "Is judgment executed by showing mercy?"
Remember, mercy (in the theological AND civil sense) is the "withholding of a deserved punishment". In order to receive mercy the necessary precondition must exist that we are guilty of
some transgression that requires punishment. Mercy is UNDESERVED abrogation of our deserved punishment. Mercy CAN NOT be deserved because if it were, then it ceases to be mercy and is rather JUSTICE.
So the question becomes, can a person be be WORTHY of MERCY? Manifestly one can not. Mercy is a decision made by God entirely upon His good will and pleasure, see EPH 1:5.
Now, if mercy is not a condition for judgment (vis-a-vis your initial statement), is the withholding of mercy by God dependent upon the actions of the sinner? Well, no, since we are already guilty, and mercy being a voluntary withholding of punishment by the Judge independent of actions or worthiness of the defendant, the withholding of mercy (i.e. execution of judgment) is already a foregone state. Mercy is a condition that supersedes the already righteous judgment of guilt of the sinner.
Now, since we can (hopefully) see that mercy is not something we can exert influence upon for our own benefit, the question, "Could God Save Everybody If He Wanted To" can be rephrased, "Was the Atonement
sufficient for all Mankind?" THAT sounds like a Calvin inspired debate if ever I heard one!
My take, Jesus, being God, offered an INFINITE sacrifice for ALL SIN, that is, IF God decided He were to have mercy on every soul who ever lived, the sacrifice of Christ would be sufficient for that decision.
HOWEVER... God is not just defined by His Mercy. His character is also defined by His Justice. Would Justice be served by applying the Blood of Christ to
everyone? I submit the answer is NO, for the simple reason if ALL were to be forgiven then the Law was for naught and God's Word to Adam would be FALSE (...you will SURELY die...).
God's justice MUST be served lest His Word is made null. So,
in potentia, the Blood of Christ is potent enough to cover every sin ever committed by every soul dead, alive, and yet to be born. But
in usum the Blood is APPLIED to those whom God PRE-destined according to His good will and pleasure (again Ephesians 1).