Such a juicy topic SECULAR! you want some Theistic material/beliefs?
In a nutshell I'll provide a couple links/descriptions so it doesn't seem like I'm just making crap up, spirituality has been around a long time so I don't claim to know anything new. I'm not strapped to any one set of ideas or religious doctrines either, I allow for all sources and forms of truth, and I evaluate them accordingly. These descriptions/beliefs below are pretty accurate.
Spiritism-
"is a spiritualistic philosophy, science, and religion ; it proposed the study of "the nature, origin, and destiny of spirits, and their relation with the corporeal world".
"Spiritism postulates that humans are essentially immortal spirits that temporarily inhabit physical bodies for several necessary incarnations to attain moral and intellectual improvement. It also asserts that spirits, through passive or active mediumship, may have beneficent or malevolent influence on the physical world.."
What Jesus taught was more than some religious doctrines and a handful of impressive/unbelievable feats of miraculous events. Underlying the Gospel testimonies are a fabric of spiritual principles, illustrations, parables, examples, lessons and teachings that support the personal growth of the soul. This does not include every denomination or religious sect and what they believe.
Christianity-
"the religion based on the person and teachings of Jesus of Nazareth, or its beliefs and practices."
Vardankar-
"is the most direct path back to God via personal experience in the pure positive God Worlds through out-of-body Tuza (Soul) Travel. It is not a religion, metaphysical system, or philosophy but does lead to the most profound and complete personal experience with God. Self Realization is not the understanding of one’s mind, emotions, or lower self but the experience of our true eternal God self Soul upon entering consciously the Soul plane or 5 th plane, which is beyond opposites, beyond the worlds of duality, and beyond matter, energy, time, space, and the mind and emotions of man."
"There are three purposes to VARDANKAR:
1. Self Realization
2. God Realization
3. Becoming a conscious co-worker with God"
This conception of the first Source is accurate. This is what it is and why we exist period. Everything in creation comes out of one Reality, including all individual souls.
Brahman-
"it is the material, efficient, formal and final cause of all that exists.[2][4][5] It is the pervasive, genderless, infinite, eternal truth and bliss which does not change, yet is the cause of all changes.[1][6][7] Brahman as a metaphysical concept is the single binding unity behind diversity in all that exists in the universe
is discussed in Hindu texts with the concept of Atman (Soul, Self)"
PanENtheism-
"Panentheism, also known as Monistic Monotheism, is a belief system which posits that the divine – whether as a single God, number of gods, or other form of "cosmic animating force" – interpenetrates every part of the universe and extends, timelessly (and, presumably, spacelessly) beyond it."
(meaning "all-in-God", from the Ancient Greek πᾶν pân, "all", ἐν en, "in" and Θεός Theós, "God")[1] is the belief that the divine pervades and interpenetrates every part of the universe and also extends beyond time and space. "
"In panentheism, God is viewed as the soul of the universe, the universal spirit present everywhere, which at the same time "transcends" all things created."
"While pantheism asserts that "all is God", panentheism claims that God is greater than the universe. Some versions of panentheism suggest that the universe is nothing more than the manifestation of God. In addition, some forms indicate that the universe is contained within God."...….
BOTH are correct however....the universe is a manifestation of God as well all the universe is contained within God, and all the multi-worlds as well. There is nothing outside the Boss or what some refer to as "Brahman" or any of the other descriptions.
Buddhism-
"All Buddhist traditions share the goal of overcoming suffering and the cycle of death & rebirth, either by the attainment of Nirvana or through the path of Buddhahood."
Samsara
Saṃsāra means "wandering" or "world", with the connotation of cyclic, circuitous change.[85][86] It refers to the theory of rebirth and "cyclicality of all life, matter, existence", a fundamental assumption of Buddhism, as with all major Indian religions.[86][87] Samsara in Buddhism is considered to be dukkha, unsatisfactory and painful,[88] perpetuated by desire and avidya (ignorance), and the resulting karma."
Karma-
"the endless cycle of suffering and rebirth for each being. Good, skilful deeds (Pali: "kusala") and bad, unskilful deeds (Pāli: "akusala") produce "seeds" in the unconscious receptacle (ālaya) that mature later either in this life or in a subsequent rebirth.[118][119] The existence of karma is a core belief in Buddhism, as with all major Indian religions, it implies neither fatalism nor that everything that happens to a person is caused by karma.
A central aspect of Buddhist theory of karma is that intent (cetanā) matters and is essential to bring about a consequence or phala "fruit" or vipāka "result".[121][note 16] However, good or bad karma accumulates even if there is no physical action, and just having ill or good thoughts create karmic seeds; thus, actions of body, speech or mind all lead to karmic seeds."
WHY? do I believe any of the above? my answers would include direct, personal experience/observation, cross referencing with a variety of sources and applying spiritual practices/principles. I evaluate claims according to what I observe about reality and what makes sense.. Probably the same reasons why you believe what you believe only some things are acquired.