"Cremation" entry in Catholic Encyclopedia: https://www.newadvent.org/cathen/04481c.htm
> By the fifth century of the Christian Era, owing in great part to the rapid progress of Christianity, the practice of cremation had entirely ceased.
> The Christians never burned their dead, but followed from earliest days the practice of the Semitic race and the personal example of their Divine Founder. It is recorded that in times of persecution many risked their lives to recover the bodies of martyrs for the holy rites of Christian burial. The pagans, to destroy faith in the resurrection of the body, often cast the corpses of martyred Christians into the flames, fondly believing thus to render impossible the resurrection of the body. What Christian faith has ever held in this regard is clearly put by the third-century writer Minucius Felix, in his dialogue "Octavius", refuting the assertion that cremation made this resurrection an impossibility: "Nor do we fear, as you suppose, any harm from the [mode of] sepulture, but we adhere to the old, and better, custom" ("Nec, ut creditis, ullum damnum sepulturae timemus sed veterem et meliorem consuetudinem humandi frequentamus" — P.L., III, 362).
What seems like an imperfect world and unfair events and illness is really a perfectly designed environment for it's purpose.
As for Heaven, perhaps a lot of our questions become irrelevant if we no longer experience linear time there?
This is off topic, but one thought that always puts a smile on my face is the possibility that God is all knowing and timeless, meaning none of our personal experiences are ever lost, instead recorded forever in God's memory.
If so, it means we have the power to choose to weave events and memories forever into the fabric of reality. To contribute moments of love and joy between our family and between ourselves and God that become part of an eternal tapestry.