Here is simple line from Ramana Maharshi
This is nirvikalpa Samadhi. This is the final step when done while doing all activities
This is a very high quality meditation. Almost all who read it should use this as a gauge to progress.
Now if you think about it, this is peace isn’t it? Not a single unwanted thought? Aah And what do the fools of the world try to do? Change their life? Instead it is better to change yourself.
Since holding the attention to the single entity – that ultimate entity is God. You can measure your closeness to God.
After all when you have God do you worry at all?