We are limited by the very fact that we have human form. There is no freedom in following our whim, or even our most reasoned decisions. As a prisoner cannot undo his own shackles, so we remain enslaved to our own limited selves.
And so Moses was told, “When you take the people out from Egypt, you shall all serve the Infinite G‑d on this mountain.”
The Infinite G‑d is the only one who is not compelled by any bounds. What makes us free? Simple deeds done each day, as agents of the One who is absolutely free.
Tanya, Chapter 47.