Hello, all-
First, let me extend sympathy for your loss during this time, and rejoice in God's mercy and grace that alleviated the suffering of your father and brought him closer to God.
I thought this was interesting, and I am limiting my response to Biblical text, as I think that appropriate for a Christian forum.
I would like to make a note regarding heaven and hell. I am not disputing the validity of the Bible, but only saying from a liberal Christian perspective that one's ideas about what heaven and hell look like can be quite different. My beliefs are very much influenced by liberal Quakerism, and I cherish the Bible. However, there are many liberal Christians who, like myself, do not believe that the Bible was meant always to be taken literally, and who also are very concerned with putting passages in their proper historical, cultural, and linguistic context. That said, I do not see hell as a "lake of fire," nor do I see heaven as streets paved in gold, or as actual places at all. Here is why:
There are two words that are translated as "hell" in English- "sheol," which meant "the grave" and "Gehenna," which was a metaphoric reference to and actual place- what was essentially the city dump with all its burning refuse, animal carcasses, etc. Judaic scripture (the OT in the original Hebrew) and Jewish tradition holds that after death several things could happen. (1) That the person could simply sleep (be in "sheol") until the Resurrection at the End of the World (excellent scriptures were given by others earlier in this thread), (2) that the person could go to the Throne of Judgment (the current belief of most Christians and also already supported by scripture). At the Throne of Judgment, one's actions and motivations in life were weighed by God. No one was perfect, but a consistent striving toward spirituality and righteousness was rewarded by eternal life through the mercy of God. Most people were understood to fail this initial judgment, and were sent to a place apart from God ("Gehenna") to learn from their actions, repent for their sins, and be purified spiritually. Jewish belief holds Gehenna was not eternal, but transitory. After this purification, they too were admitted into eternal life. Many Orthodox Jews held that some were reincarnated, either to learn lessons that had missed on earth or to help others along their path. Many Orthodox Jews held that the supremely wicked, who extinguished all goodness in themselves, simply ceased to exist after death, having severed the tie to the elements of their soul that were spiritual.
In the NT, we find three versions of hell. The first two, again are "sheol" and "Gehenna," which are referenced by Jesus in the gospels. The third is this idea of everlasting fire that Satan and the demons will be cast into. The third is problematic for a number of reasons, most notably that it is not in line with the Old Testament scriptures concerning hell and Satan, and as the Messiah, Jesus would have been Jewish and He says through the gospels that He did not come to demolish the law and prophets, but rather to fulfill them (Mt 5:17). How one reconciles this is up to the denomination and beliefs one has. Suffice it to say that some of us believe that just as Gehenna was an actual place that served a metaphoric reference to the agony of one outside the presence of God, so too is the lake of fire a reference to the total annihilation of evil and sin.
As for heaven, it is spoken of as the realm of God in the NT (Mt 3:17, 6:1&9, 7:11; Lk 11:13, Heb 1:3, 8:1, 9:24). The use of the word heaven- "shamayim" in Hebrew and "ouranos" in Greek- is the same use as the "heavens"- the created universe beyond earth. The dual use of the word for "heaven," one meaning the spiritual realm of God and the other meaning what we would now call outer space, maintains the dualism seen in Hebrew cosmology from the OT, which we can see in passages such as Isa 55:9. Yet we know that God is not confined to heaven, for He also interacts with us on earth, and one day the earth and heaven will not be separated when God's will is done on earth as perfectly as it is now in heaven (Mt 6:10). That the word for God's spiritual realm corresponds to the word for the universe outside earth indicates that it, too, is a metaphoric reference that is not so much a location as a timeless dimension of spirituality with God that touches the earth though it is currently distinct from it. Thus, Paul speaks of us having citizenship in heaven (Phil 3:20), our treasures are to be laid up in heaven (Mt 6:20), and heaven is our true home (Eph 3:19, Heb 12:22). Reading such passages metaphorically, it is not that we literally lay up treasure in heaven, for example, but that we are striving toward living in this spiritual realm even now, so that our heart is always on God, welcoming His presence. After death, we are freed from the limitations of our bodies, societies, and brains and are free to be in God's presence in this spiritual and timeless dimension.
I suppose it comes down to whether you are reading the Bible as poetry (metaphoric text that needs interpretation aided by the Holy Spirit) or as prose (literal text that is straight forward). I lean toward reading it as poetry. Heaven, for me, is nothing short of being in the presence of God, free from my body, earthly struggles, and the limitations of my brain. Hell is nothing short of the agony that is living outside God's presence. No physical manifestation, to me, can come close to either the bliss or the agony of the soul in these states. They are, to me, metaphors to help us understand the states of being that are heaven and hell.