Jesus was speaking to a Jewish audience who had no belief in an afterlife. I am not wrong about that verse.
That's actually strictly not true.
By the 6th century BCE Exile and the Second Temple period, some Jews were influenced by the religions of their conquerors - the Neo-Babylonian and the Persian.
For example, before the Exile, there were no writings (scriptures) where angels were not nameless. Then suddenly personal names were given: Michael, Gabriel and Satan.
That because Zoroastrianism had spread west into Babylonia during the 5th century, where Zoroastrian angels have personal names.
And by the Hellenistic period, they were influenced by the Greek and Egyptian religions. And by this time' non-canonical texts began appearing, known collectively as the Apocrypha (like Tobit) and Pseudepigrapha (like 1 Enoch, 2 Enoch, Book of Jubilees, Assumption of Moses, etc).
More angels with names began popping up, starting with 1 Enoch. Here, we began seeing fallen angels, known as the Watchers or the Grigori. This is when the character of Satan began to change.
What the gospels called "demons" were clearly derived from 1 & 2 Enoch.
Enoch who played only a very tiny part in the OT, is mostly known for being Noah's great grandfather. But in these Hellenistic books, he plays the hero and became the scribe of God, later known in Jewish tradition (Talmud, Midrash) and folklore (3 Enoch, Aggagah, Kabbalah) written after the Destruction of Jerusalem in 70 CE, as Metatron.
1 Enoch and 2 Enoch written before Jesus' time, include Enoch visit to heavens, witnessing angels. In 2 Enoch it say that the Watchers were imprisoned and punished in the 3rd heaven and particularly in the 5th heaven. In the 3rd heaven, fallen angels weren't the only ones being punished; people (humans) who have been wicked were also locked up and tormented here.
But place of torment for people in the afterlife, were clearly influenced by Jews interaction with the Greeks and Egyptians. During the 3rd and 2nd centuries, said to be the time, when that some Jews had migrated to Egypt and also when they were translating the Hebrew scriptures into Greek, as well as the Enochian texts and Book of Jubilees, were influenced by Greek images of Tartarus and Egyptian Duat.
The idea of afterlife in heaven, were also mostly influenced by the Greek Elysian Field and Blessed Isle, and Egyptian Osiris. Even the whole martyr and resurrection of Jesus weren't original, and most likely originate either from the Greek Orphic cult or the Egyptian Osiris.
Osiris was the god that die, and resurrected, ruling the Netherworld. Osiris was the one who decide who should go to the Egyptian versions of heaven or hell, during the Judgement (the weighting of the soul (known as
ba, which is usually represented as a heart) against the feather of Ma'at, goddess of truth and cosmic order), but Osiris had final say.
Below, is the drawing from the Book of the Dead, Papyrus of Ani (c 1250 BCE).
Osiris is the seated figure on the right, behind him is his sisters Isis (wife) and Nephthys. The man in white appear twice robe, is the same person, the decease and the one being judged, most likely to be Ani.
Under the scale, the creature kneeling next to jackal-headed Anubis, is called Ammit, the Devourer - with crocodile head, and lion-hippo body. If the ba (soul) is heavier than the feather, it would mean the decease is sinful, so Ammit swallow the soul, the spirit go to Duat, the Egyptian version of Greek Tartarus and Christian Hell.
Ammit was said to reside in the "Lake of Fire". Does that not ring a bell to you?
And due to these influences upon Hellenistic Jews, Christians made use of these pre-Christian texts.
Jesus certainly didn't invent concept of the afterlife...not even to the Jews.