Believers in deities often claim that because secularism is deterministic, it has no room for free will and therefore has no concept of personal responsibility or morality. But I don’t see how free will entails moral responsibility, and I don’t see that responsibiltiy entails free will.
To take the first implication direction: free will is an incoherent notion. If there is no motive or source of a decision, then the decisions are not tied to an integral self — they’re just random decisions, that don’t belong to anyone. If a decision is motivated by some determinant, then the decision isn’t free. To put it in a theological context: either god made you who you are, and she is responsible for every decision thereafter, or your decisions are random and not anchored is a self. So free will doesn’t entail responsibility. It entails no responsibility, because it entails no self. End of story.
From the other direction of entailment: the individual can hold herself responsible just to flatter herself for believing she’s an integral self. And what do you know, that’s exactly how we all feel. Responsibility is an illusion that works. You don’t need free will, only the illusion of self.