Would God have had Jesus appear to everyone (or more)?
Reportedly, God raised Jesus from the dead and had Jesus present himself alive to a relatively small pool of witnesses. If God existed and raised Jesus from the dead, wouldn't he have had Jesus appear to more witnesses, like the Pharisees, or the Jews at large, or perhaps to all the world up until the present? 
Richard Carrier: “Why on earth would a God, who wanted to save all mankind, only appear to a few hundred, most unnamed, people and then give up? Wouldn't it be much more efficient and effective… to bypass the apostolate and just appear to everyone?” [“The Spiritual Body of Christ,” in Price and Lowder, Empty Tomb (Prometheus Books, 2005), 195)]
(This is at least loosely connected to the so-called problem of divine hiddenness, which asks, “If a loving God existed, wouldn't God ensure we always know it so we can have relationship?”)
- 1 Timothy 2:4 says “[God] desires all men to be saved and to come to the knowledge of the truth.” Consequently, many Christians do grant this premise, but many others in fact disagree. After all, {desiring x} is not necessarily {willing x}. One can have competing desires. God can have a desire to save all men and simultaneously a competing desire to condemn all men, much like one can both desire to stay in bed in the morning and a competing desire to get out of bed. Consider:
◦ From a scriptural perspective; several scriptures indicate God's desire to bring judgment on the wicked (i.e. all humanity), ◦ Prima facie God, as the greatest possible being, would have both of these competing desires. What God goes on to will, however, is what sometimes gets called one's “ultimate desire” and designates which of God's desires He has chosen to bring about. - It is far from clear that the way things were done is not the better. It's hard to say how many people would be in relationship with Christ if He appeared to all persons individually. Humans might respond and encourage each other to respond in rather unpredictable ways. It is not clear that the way things were done wasn't best for the end, where people come to know Christ through evangelism and referral from friends/family/helpers who themselves came through friends/family/helpers. Consider the following:
Mike Licona: “Whatever reason God had for doing it that way, it worked. Nearly a third of the people of the world today claims to be Christian. And I think it's just like the Christian God to use the weak to trump the strong, and the fools to shame the wise. It would be just like that God to take the few and the obscure to influence the masses. Now, because of that, the world has been turned upside down.” [Lee Strobel, The Case for the Real Jesus (Zondervan, 2014), 153.]
God wills for all humans to freely enter into relationship with him.1 This is relevant because Jesus's appearing to all persons in the world would best accomplish this.2
By way of response, however,…
• The bolded claim is false.1
• The non-bolded follow-up claim is also false.2
- There are two reasons to think the bolded claim is false:
• FIRST: No seminary, scripture, church father, or Christian philosopher has taught that God is doing his best to bring everyone to mere belief in Christianity. (See the section of Divine Hiddenness) On Christian theism, at best God wills all of us to freely enter into relationship with Him, and thereby be saved. If God willed for all to merely believe Christianity is true, then God would just bring that about directly (with a metaphorical snap of his fingers). It needs to be noted that the way in which God brings people to belief in Christianity could drastically influence the likelihood that they would choose to freely enter into relationship with Him. For example, it's not clear that the way things were was not best, where people come to know Christ through evangelism from friends/family/helpers who themselves came to relationship with Christ through friends/family/helpers.
• SECOND: It's unclear or even false that God wills all humans to freely to enter into relationship with Him. So a fortiori it does not follow that God wills for as many as possible to mentally assent to Christianity. - There are ways which are far more effective at getting individuals to mentally assent to the truth of Christianity. We know this because resurrection appearances leave a lot to be desired.
Luke 16:31 -- But he said to him, ‘If they do not listen to Moses and the Prophets, they will not be persuaded even if someone rises from the dead.’” Matthew 28:17 -- When they saw Him, they worshiped Him; but some were doubtful. Such appearances would do nothing for solipsists (who believe they are in a dream world), or individuals who would simply be convinced a demon or alien is tricking them. If God willed for all to merely believe Christianity is true, then God would just bring that about directly (with a metaphorical snap of his fingers).
God wills for as many people as possible mentally assent to the truth of Christianity.1 This is relevant because having Jesus appear directly to all persons is the most efficient means by which God could bring about this result.2
By way of response, however,…
• The bolded claim is false.1
• The non-bolded follow-up claim is also false.2
Getting humans to reason from resurrection evidence to the truth of Christianity is the only or primary way God would desire bring someone to belief that Christianity is true. This is relevant because Jesus's appearing is the best or only way to get us to reason from Jesus's resurrection to the truth of Christianity.
By way of response, however,
• There is no evidence given for the bolded claim.
• The bolded claim falsely implies that God doesn't want people to come to faith…
― …by personal spiritual experience.
― …by testimony from trusted persons (like one's parents, evangelists, professors).
― …by dreams (as in the case of many Muslims).
― …by other means.
• it is unclear or false that God does not will for all to believe in Christianity.