As physicist and mathematician Prof. Frank J. Tipler noted, "Any cosmology with unlimited progress will end in God." (See Anthony Liversidge, interview of Frank Tipler, "A Physicist Proposes a Theory of Eternal Life that Yields God", Omni, Vol. 17, No. 1 [Oct. 1994], pp. 89 ff. [8 pp.].) This means that, e.g., any form of immortality necessarily entails the existence of the capital-G God, in the sense of an omniscient, omnipotent and personal being with infinite computational resources. This is mathematically unavoidable, for the reason that any finite state will eventually undergo the Eternal Return per the Quantum Recurrence Theorem. This is very easy to see by considering the simple example of two bits, which have only four possible states (i.e., 2^2): hence, once these four states have been exhausted, states will have to recur. What that means is that any finite state can only have a finite number of experiences (i.e., different states), because any finite state will eventually start to repeat.
Thus, immortality is logically inseparable from the existence of the capital-G God, since mathematically, immortality requires the existence of either an infinite computational state or a finite state which diverges to an infinite computational state (i.e., diverging to literal Godhead in all its fullness), thus allowing for states to never repeat and hence an infinite number of experiences.
Consequently, transhumanism--if the goal by that position is immortality--is inherently theistic, not only in a lowercase-G god sense, but also in the capital-G God sense.
Interestingly, this also means that the existence of biological evolution, far from demonstrating that God is unnecessary, is in fact a logical proof of God's existence *unless* one posits the additional postulate that there is a limit to evolution. Yet there is no logical limit to evolution other than infinite complexity; and there exists no empirical evidence that evolution is finitely-bounded. Thus, to believe that evolution has a finite cut-off would be to hold a belief without evidence, and thus it would be an irrational belief.
The concept of man being gods and becoming ever-more Godlike is simply traditional Christianity, going all the way back to Jesus's teachings (e.g., see John 10:34), that of Paul and the other Epistlers, and that of the Church Fathers. In traditional Christian theology, this is known as apotheosis, theosis or divinization. For many examples of these early teachings, see the article "Divinization (Christian)", Wikipedia, Nov. 4, 2019, https://en.wikipedia.org/w/index.php?title=Divinization_(Christian)&oldid=924591789 , https://archive.is/VhJpa . Though this traditional position of Christian theology has been deemphasized for the last millennium.
Indeed, the words "transhuman" and "superhuman" originated in Christian theology. "Transhuman" is a neologism coined by Dante Alighieri in his 1320 work Divine Comedy (Paradiso, Canto I, lines 70-72), referring favorably to a mortal human who became an immortal god by means of eating a special plant. For the Christian theological origin of the term "superhuman", see the Oxford English Dictionary (2nd ed.), the first appearance being by Henry Montagu, 1st Earl of Manchester, in his Al Mondo: Contemplatio Mortis, & Immortalitatis (London, England: Robert Barker, and the Assignes of John Bill, 1636).
Moreover, Prof. Tipler's Omega Point cosmology is a proof (i.e., mathematical theorem) demonstrating that sapient life (in the form of, e.g., immortal superintelligent human-mind computer-uploads and artificial intelligences) is required by the known laws of physics (viz., the Second Law of Thermodynamics, General Relativity, and Quantum Mechanics) to take control over all matter in the universe, for said life to eventually force the collapse of the universe, and for the computational resources of the universe (in terms of both processor speed and memory space) to diverge to infinity as the universe collapses into a final singularity, termed the Omega Point. Said Omega Point cosmology is also an intrinsic component of the Feynman-DeWitt-Weinberg quantum gravity/Standard Model Theory of Everything (TOE) correctly describing and unifying all the forces in physics, of which TOE is itself mathematically forced by the aforesaid known physical laws.
Since the aforementioned known laws of physics have been confirmed by every experiment to date, the only way to avoid Prof. Tipler's Omega Point Theorem is to reject empirical science. As Prof. Stephen Hawking wrote, "one cannot really argue with a mathematical theorem." (From p. 67 of Stephen Hawking, The Illustrated A Brief History of Time [New York, NY: Bantam Books, 1996; 1st ed., 1988].)
Prof. Tipler's Omega Point cosmology has been extensively peer-reviewed and published in a number of the world's leading physics and science journals, such as Reports on Progress in Physics (the leading journal of the Institute of Physics, Britain's main professional organization for physicists), Monthly Notices of the Royal Astronomical Society (one of the world's leading astrophysics journals), the International Journal of Theoretical Physics (a journal that Nobel Prize in Physics winner Richard Feynman also published in), and Physics Letters, among other journals.
Prof. Tipler's Ph.D. is in the field of Global General Relativity, which is the field created by Profs. Stephen Hawking and Roger Penrose during the formulation of their Singularity Theorems in the 1960s. Global General Relativity is General Relativity applied on the scale of the entire universe as a whole, and is the most elite and rarefied field of physics. Tipler is also an expert in quantum field theory (i.e., Quantum Mechanics combined with special-relativistic particle physics) and computer theory.
The Omega Point final singularity has all the unique properties (quiddities) claimed for God in the traditional religions. For much more on Prof. Tipler's Omega Point cosmology and the details on how it uniquely conforms to, and precisely matches, the cosmology described in the New Testament, see my following article, which also addresses the societal implications of the Omega Point cosmology:
* James Redford, "The Physics of God and the Quantum Gravity Theory of Everything", Social Science Research Network (SSRN), Sept. 10, 2012 (orig. pub. Dec. 19, 2011), 186 pp., doi:10.2139/ssrn.1974708, https://archive.org/download/ThePhysicsOfGodAndTheQuantumGravityTheoryOfEverything/Redford-Physics-of-God.pdf , https://purl.org/redford/physics-of-god , https://webcitation.org/74HMsJGbP .
Additionally, in the below resource are different sections which contain some helpful notes and commentary by me pertaining to multimedia wherein Prof. Tipler explains the Omega Point cosmology and the Feynman-DeWitt-Weinberg quantum gravity/Standard Model TOE.
* James Redford, "Video of Profs. Frank Tipler and Lawrence Krauss's Debate at Caltech: Can Physics Prove God and Christianity?", Apr. 18, 2019, https://pastebin.com/6bZDc7rB , https://archive.is/uHEyL , https://megalodon.jp/2019-0423-0435-52/pastebin.com/6bZDc7rB .