It depends on what your work is and if the new venture you are going into are more profitable and proven as a winning concept to replace your
income from your current job. I have friends who
lost their jobs and who are working freelance for Bitcoin and they are struggling at the
moment. { The market is still small }
I would first go into it part-time and then see how it goes, before I leave my current job and go all out into Bitcoin.

I agree with this. I think the vast majority of Bitcoin community are doing just that. Yes, we eagerly want to go full time on Bitcoin but unfortunately we can't do that yet because the amount we can earn with Bitcoin is too little to provide for our daily needs.
Of course there are exceptions and I respect those people with all my heart.