To encounter the vast space within oneself,
One has to dive into the deepest oneself without any judgment or thoughts, and get the highest perspective simultaneously.
This means that you can know the spiritual experience as knowledge but if you really want to understand it, there is no way to realize it except in a way that you sense it yourself bodily, rather than you imagine.
And when you sense it, you will surely have conviction without any doubt.
Bruce Lee also said, “Don’t think. Feel.”