Voltaire was talking about the chains of authority and power and the incomprehensible irony not only of enslaved people’s resignation to their fate, but of the sense of security those chains gave them. You will not be surprised to hear me make the obvious application to the chains of religious belief. Some believers have said explicitly to me that they could never abandon their beliefs, though they sometimes had serious doubts about the truth behind many of them, because that would leave them not only helpless but hopeless. They do not realize that this amounts practically to a recognition that faith is born of wishful thinking.
The metaphor of chains is entirely appropriate. Only acceptance of the truth of atheism will make us free of the shackles put on our minds when we were children. The good news is that we can remove the shackles all by ourselves. To use another metaphor, we just need to take off the blinders and blinkers. “Free at last, thank whatever you like, free at last !”. “I was blind but now I see !”.