Kabir, Buddha Nanak... Everything was an illusion then, and it hasn't changed. Even the "heavens" are an illusion, but they are LESS of an illusion than the physical.
The reason there is only one way to God is because we are all created the same-we all have the same inner structure. The kundalini, the chakras, etc. This is how we are created--from the inside out. And this is how the physical body is animated. It's an on-going thing. We pre-exist the physical body, and the various subtle bodies pre-exist each other--the more subtle, the further inside. There are no exceptions to this.
The only way back is the way we came. Now...there are different methods of doing that, but at some point these methods merge.
Many of the methods attempted to merge back into God do not work because they were devised in a higher age and don't translate into this lower, totally physical age with it's shortened life span. Hatha yoga, and most other yogas, for example...