I do think that is true, that we can do without "God" and "Spirituality", but it's usually much harder for people to work hard to get to the point of Self Realization (let go of all attachments), in which there is Free Will, as one is no longer chained to the wheel of Karma (past actions influencing us), hence one is really free, hence Free Will. But Self Effort, purifying from all attachments is essential to claim "I have Free Will"
If attachments increase one is never free, hence no Free Will
Buddha meditated and reached that state of freedom
If there is "no mind" then there is Free Will
@Policy did start a very interesting topic
Thank you for all your feedback, you got me get up, and think a bit deeper with all these terms. And I got myself reminded the importance and power of Self Effort. I like the term Self Effort, as it is very practical, urging us to purifiy our thoughts, words and deeds, and from there difficult concepts suddenly become simple, without even have to study about it. I experienced this many times, hence I usually don't busy myself with philosophical questions like "Free Will, do we have it or not?". But it was nice for a change