1. My understanding is that everyone will be judged when Jesus returns, so there are currently people who died up to around 2000 years ago, where are their souls now?
There is confusion and disagreement about what the words hell, gehenna, sheol, hades, and the phrases, in the grave, Abraham's "bosom" (from Luke 16:19-31), and others refer to, and who was there before Christ and who is there now. The "lake of fire" is separate from these, but in the end, I personally just lump them into "the place(s) of eternal torment." I doubt anyone who lands there (or does not) will care about the distinctions.
However, I should mention that the degree of torment will not be the same for everyone (Luke 12:47-48), although it will be incomprehensibly awful for everyone. The attributes of God will not exist in hell (love, joy, peace, patience, kindness, goodness, faithfulness, gentleness, self-control, compassion, forgiveness, etc.) which includes life as we can understand it (God is the source and sustainer of Life.)
2. What happens to babies/ infants/ children who die? If they are very young how can they have made a decision to follow Christ, so what happens to their souls? How are they judged? If a child is brought up in a (say) very strict Muslim house and dies at (say) 14 years old, how are they judged?
If parents raised a child to believe in the Bible and Jesus and salvation by believing what he said, would it be moral for that to affect the child's ability to choose to follow Christ or not? Wouldn't the reverse be true as well?
Everyone is born separated from God and on the path to hell, because we inherit a sinful nature from our parents. Jesus died to pay for everyone's sins, but if one does not know about him, his sacrifice, or have not yielded to his Lordship, then he cannot avoid where his nature has him headed. Yielding to God is a necessary moral component for him to save someone. This is very hard for some people to accept, and I think it always will until one recognizes the truth of how evil humans are in their nature. Everyone deserves eternal punishment because anything tainted with sin cannot withstand God's pure presence. His glory emanates from him. People tainted with sin who were visited by angels on earth fell down with no strength and would have died if left in that state (the symptoms sound a lot like shock). Learning this requires knowing God, who does not change, rather than taking cues for what is moral from our ever-changing society. It begins as an intellectual pursuit, since it is so far from what we are used to.
There is a kind of sense in which this is unfair, however, the fault lies squarely with Christians and not with God. Jesus commanded his disciples to go into all the world to tell people about him. But most Christians have behaved like everyone else and not like Jesus commanded. It is humans who are responsible for the ministry of reconciliation with God (from 2 Corinthians 5:18-20).
if my people, who are called by my name, will humble themselves and pray and seek my face and turn from their wicked ways, then will I hear from heaven and will forgive their sin and will heal their land. (2 Chronicles 7:14, 1984 NIV)
In spite of terrible Christian failings, God wants to save everyone and works to that end, but he won't override anyone's free will.
However, there is hope for everyone,
since what may be known about God is plain to them, because God has made it plain to them. For since the creation of the world God’s invisible qualities—his eternal power and divine nature—have been clearly seen, being understood from what has been made, so that men are without excuse. (Romans 1:19-20, 1984 NIV)
for, “Everyone who calls on the name of the Lord will be saved.” (Romans 10:13, 1984 NIV)
On this topic, the Lord showed me the passage in which this verse appears:
Therefore God has mercy on whom he wants to have mercy, and he hardens whom he wants to harden. (Romans 9:18, 1984 NIV)
As in all things, God does what he chooses, but we can move his heart in one direction or another.
Unfortunately we are living in a time of "darkness," where everyone has a bad case of spiritual blindness (as predicted by Jesus) that makes it hard for anyone to recognize the truth. Consider how different our culture is from one where everyone is doing what God said to do (and what not to do). It hasn't always been as bad as it is now.
3. Is the only choice between a Heaven with eternal life in paradise and Hell with eternal life in damnation, fire and all that goes with it. Are Heaven and Hell physical places?
Scripture always speaks as if these are real places. A person cannot justify the existence of heaven without justifying the existence of hell. If one believes God made everyone to exist forever, then what happens to someone when they die if they don't go to heaven or hell? There is no "annihilation" in Scripture, which, by the way, would require God to act immorally. People don't get into heaven because they have not genuinely accepted Christ's payment for their sins, and their sin remains a part of them, so they have to pay for their own sins for justice to be served. God sacrificed his son so humans wouldn't get what they earned for themselves, but people prefer to reject him and do what they want (sometimes called "being their own God").
The fact that the payment is torment forever does
seem unfair, but we can at least try to recognize that everyone will exist forever and nothing can change that—that's how God created us. His goal was to create humans in his likeness, and he succeeded (of course). Every sin is a form of rejection of God ("I want to set my own moral standards"), and every sin is against an eternal being who is our creator. People who persist in rejecting God will get exactly what they wanted: existence without God.
4. Are you supposed to be physically resurrected, if so presumably you never age therefore what age are you at this physical resurrection? If you die as a child or teenager are you resurrected into the body you would have had later?
I don't know in what way our age at the time of our death will affect us. We will all get new and different bodies (1 Corinthians 15:35-38). Note that heaven is not the final destination of saved people. God will remake the earth (without the effects of sin) and there will be a "New Jerusalem" where we live with God. There isn't a lot of detail about that, so it lends itself to human imagination for more detail (along with many other things that aren't explained in Scripture).
