Complex sentence: Magilums (Ships of the death) were funeral boats used in ancient Sumerian pantheon was mostly based on an agricultural belief system, water was used as a passage to different planes and the gateway to the afterlife.
Split into simpler sentences: Magilums (Ships of the death) were funeral boats used in ancient Sumer. As the Sumerian pantheon was mostly based on an agricultural belief system, water was used as a passage to different planes and the gateway to the afterlife.