You’ve Got to Have Soul!
This dismissal of a bridged consciousness and dualism strike at the heart of another key part of religion.
I’d argue that souls, instead of god, are the common thread between religions. Every religion I’ve encountered has them, no matter how many gods they worship:
And Jehovah spake unto Moses, saying,
When thou takest the sum of the children of Israel, according to those that are numbered of them, then shall they give every man a ransom for his soul unto Jehovah, when thou numberest them; that there be no plague among them, when thou numberest them.
(Exodus 30:11-12, Old Testament, American Standard Translation)
I bow down to those who have reached omniscience in the flesh and teach the road to everlasting life in the liberated state.
I bow down to those who have attained perfect knowledge and liberated their souls of all karma.
I bow down to those who have experienced self-realization of their souls through self-control and self-sacrifice.
I bow down to those who understand the true nature of soul and teach the importance of the spiritual over the material.
I bow down to those who strictly follow the five great vows of conduct and inspire us to live a virtuous life.
To these five types of great souls I offer my praise.
(The first six lines of the Namokar Maha Mantra, the “universal” prayer of Jainism)Never is he (Soul) born, nor does he die at any time, he has never been brought into being, nor shall come hereafter; unborn, eternal, permanant and ancient (primeval). When the body is slain, he is not slain. \
O’ Arjunaa, know this soul to be eternal, undecaying, birthless and indestructible. A person who knows him to be so — whom can he slay or cause another to slay.
As a man casts off worn-out garments and puts on new ones, so the embodied soul casts off the worn-out body and enters other new ones.
(Chapter 2, verses 20-22, from Srimad Bhagavat Gita, a Hindu holy text)
The concept of the soul requires two things, that consciousness be detachable from the brain, and that this consciousness have some non-material place to inhabit. With both in place, death becomes an annoyance instead of a finality, thus evaporating the biggest fear of any conscious organism. As an added bonus we can bolt on a system of punishment, to take care of anyone who got away with murder while alive.
In some religions this non-material realm sounds suspiciously like the material one:
Lo! those who kept their duty dwell in gardens and delight,
Happy because of what their Lord hath given them, and (because) their Lord hath warded off from them the torment of hell-fire.
(And it is said unto them): Eat and drink in health (as a reward) for what ye used to do,
Reclining on ranged couches. And we wed them unto fair ones with wide, lovely eyes.
And they who believe and whose seed follow them in faith, We cause their seed to join them (there), and We deprive them of nought of their (life’s) work. Every man is a pledge for that which he hath earned.
And We provide them with fruit and meat such as they desire.
There they pass from hand to hand a cup wherein is neither vanity nor cause of sin.
And there go round, waiting on them menservants of their own, as they were hidden pearls.
(Sura 52:17-24, The Qur’an, translated by M.M. Pickthall)
After these things I saw, and behold, a door opened in heaven, and the first voice that I heard, [a voice] as of a trumpet speaking with me, one saying, Come up hither, and I will show thee the things which must come to pass hereafter.
Straightway I was in the Spirit: and behold, there was a throne set in heaven, and one sitting upon the throne;
and he that sat [was] to look upon like a jasper stone and a sardius: and [there was] a rainbow round about the throne, like an emerald to look upon.
And round about the throne [were] four and twenty thrones: and upon the thrones [I saw] four and twenty elders sitting, arrayed in white garments; and on their heads crowns of gold.
(Revelations 4:1-4, New Testament, American Standard Translation) 
In others, this non-material realm is never described, or slightly inconsistent:
In coming and going, birth and death an apostate loses honour.
By serving the True Guru man attains to eternal peace and his light merges with the Supreme Light.
The service of the Sat [True] Guru is extremely ease-bestowing and by it one obtains the boon that he desire.
By placing Lord God in the mind continence, truthfulness and penance are obtained and the body becomes pure.
Such person ever remain happy day and night and procures peace by meeting the Beloved.
I am devoted unto those, who have sought the protection of the True Guru.
In the True Court they obtains true honour and are easily absorbed in the True Lord.
Nanak, through associating with the society of the Exalted Guru one meets the Lord by His grace.
(from pg. 31 of the Sri Guru Granth Sahib, primary holy text of the Sikh, as translated by Bhai Manmohan Singh)
The exceptions, most notably deism and to some degree pantheism, lean on dualism instead. They can’t rely on the supernatural, but still yearn for a connection to something greater than themselves. Invoking a world of ideas allows them that comfort, without having to return to the messy contradictions of a traditional faith.
If consciousness is anchored to the brain, and a perfect world of the intellect is impossible, then dualism is as likely as an afterlife with a couch.
 I’ll develop this more in the Popularity proof, when I propose an explanation for religion’s origins.
 To add to the confusion, both Islam and Christianity have an different version of “heaven” in some sects. Instead of an eternal paradise after death, you decompose and lose consciousness until the end times, at which point all the good little believers will be given new bodies and brought back to life. This version doesn’t require souls at all.