Now, you're shifting the burden of proof.
Burden of proof is a nonsensical concept in this context, because God is an initial and necessary assumption in Christian framework.
Apologetics, as the name should convey, isn't about proof. It's about defending assumptions that we find necessary to structure coherent framework of reality.
For example I can assume that the murder is wrong based on certain logic of my conceptual framework. I can't prove that the murder is wrong to someone who hold a vastly different sets of assumptions, but I can defend my assumptions using certain rationalizations driven by certain demonstrable concepts.
So, I could say that experience is better than non-exprience, and since murder is a forceful and undesired termination of experience, it means that it'll be in the very least viewed as wrong by the victim. So, then if can put ourselves in the shoes of the victim (via categorical imperative test), then if everyone was trying to murder everyone, then we see that murder is not desirable, hence it's wrong.
Yet, one could argue that it doesn't prove that murder is wrong. It just proves that it's undesirable, and there are many contextual and collective desires that can override one set over the other. We can collectively agree that murdering one set of people is ok, while other is not, and we've done so plenty in our history. So, in a setting of competing desires, one person will not see why desire alone is a rational approach to murder, especially since they may really want to terminate someone's life.
So, there isn't anything I can do in order to prove that it would be wrong for you to murder me, if you start with lack of belief that murdering me is wrong and a strong desire to do so.
So, the very reason we have contractual legal system is precisely that we can't really prove to each other certain necessary moral concepts, so we standardize these as contractually-agreed upon assumptions. We collectively and provisionally agree certain necessary concepts. And we perpetuate these assumptions through education and legal enforcement.
So, we basically say... no we can't prove that murder is wrong. All we can prove is some utilitarian approach to abstaining from murder in some contractual societal setting. So, we can collectively prefer to have that setting more than other settings, and so we canonize certain assumptions into a legal contractual structure, even if we don't have philosophical or a scientific proof that these are wrong.
These become real and wrong because we grant these provisional validity in certain setting that we prefer to maintain. And such assumed concepts can be shown necessary for both structuring and maintenance of these settings.
Again...
These become real and wrong because we grant these provisional validity in certain setting.
Concept of God is similar. I can appeal and communicate why concept of God would provide certain provisional direction when it comes to structuring one's moral map of reality. So, if we begin with assumption that God exists, then such view of reality would be different than the one in which God wouldn't exist. And certain behavior "as though God exists" could be proven more "productive" for our species.
Hence, I don't have to prove that belief in God is a true belief in your utilitarian context that looks to rationally and skeptically seek to interpret evidence via a possible explanation as to why it's not so. All I need to do as Apologist is to show you that that believe in God is more adequate than it is not in context of certain societies that agree to believe that concept or historically held it as true. And surprise! You are living in one.