It's important to not get one-sided in our approach to meditation and spirituality. After all, oneness is a laudable goal, even if it can't be attained perfectly.
(If there truly was only one, there would be no one else to know there was only one, so oneness would never be experienced.)
A one-sided coin doesn't exist. It takes two sides to make a coin.
So we shouldn't get locked into a single way of looking upon oneness. Many commenters on this blog appear to be so enamored with transcendence -- leaving this world behind to find a better one -- they forget that a big chunk of humanity embraces Taoist and Buddhist approaches to oneness that are focused on immanence rather than transcendence.
Here's passages from Jeremy Lent's book, The Web of Meaning, where he discusses transcendence and immanence.
Later in his "Everything is Connected" chapter he investigates the question, "Could the sense of immanent oneness described in traditions such as Taoism, Buddhism, and many Indigenous cultures be commensurate with these insights of modern science?"
I'll share his answer to that question in another blog post.
A critical step is to recognize that even among those who describe a vision of oneness, different cultural assumptions generate important distinctions over what that oneness signifies.
Some traditions -- such as Vedic, Neoplatonic, and Christian -- emphasize transcendence as the route to the realization of oneness. Transcendence, which means literally to 'climb over,' implies that the world as we see it, with all its messy details, must be left behind to achieve a state of unity.
The higher you go, the purer and more visionary you become, until ultimately you might reach a state of communion with divinity up in the heavens.
...The underlying idea that 'higher is better' is so embedded in language and culture that it has shaped our patterns of thought.
When we hear about a 'peak experience,' a 'higher purpose' or the 'high point' of a journey, we instantly know that the references to height denote something good. Is it any wonder that we conceive of spiritual knowledge as something reached by transcendence?
But transcendence is not the only path for attaining a state of oneness.
An entirely different way to conceive oneness is through immanence (coming from the Latin for 'remain in'). From this perspective, oneness is not found in the heavens but is right here, in this world with all its disorderly muddle.
The immanent view of oneness came naturally to the Chinese, who had no concept of a transcendent, omniscient God.
'One takes the mass of confused things,' said Zhuangzi, the Taoist sage, 'and unites it as one ... For him who can but realize his indissoluble unity with the whole ... death and life, end and beginning, are no more than the succession of day and night.'
The Tao, Zhuangzi explained, is to be found everywhere in the world, not just in a transcendent realm: it is in the ants, the grass, the earth -- even in the 'piss and shit.' Zen Buddhism, influenced strongly by Taoism, similarly taught that enlightenment was to be found within the mundane realities of everyday life.
Master Rinzai, founder of a major branch of Zen, declared, 'If you love the sacred and despise the ordinary, you are still bobbing in the ocean of delusion.'