The ones who do not come to repentance reject that which God "grants" to them. It's not that they can't believe ... it's that they reject that which is to be believed, even though what is to be believed has been revealed to them.
Scripture plainly tells us that the Lord Jesus Christ died for the whole world ...
John 1:29 The next day John seeth Jesus coming unto him, and saith, Behold the Lamb of God, which taketh away the sin of the world.
John 3:16-17 For God so loved the world, that he gave his only begotten Son, that whosoever believeth in him should not perish, but have everlasting life. For God sent not his Son into the world to condemn the world; but that the world through him might be saved.
1 John 2:2 And he is the propitiation for our sins: and not for ours only, but also for the sins of the whole world.
Scripture is also clear that God reveals Himself and some reject God ... not because they do not have faith, but because they suppress/restrain the truth in unrighteousness:
Romans 1:
18 For the wrath of God is revealed from heaven against all ungodliness and unrighteousness of men, who hold the truth in unrighteousness;
19 Because that which may be known of God is manifest in them; for God hath shewed it unto them.
20 For the invisible things of him from the creation of the world are clearly seen, being understood by the things that are made, even his eternal power and Godhead; so that they are without excuse
Rom 1:18-20 tells us that God makes plain His eternal power and Godhead ... however, this truth is suppressed. The words "who hold" in vs 18 are translated from the Greek word katechō which means to suppress; hold back; restrain. When the Word of God is spoken, the hearer restrains the truth from reaching his/her heart.
It is clear from vs 19 that God reveals His eternal power and Godhead and it is clear from vs 18 that it is the person who rejects God.
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