“That which was from the beginning, which we have heard, which we have seen with our eyes, which we have looked at and our hands have touched–this we proclaim concerning the Word of life.” -1 John 1:1
The concept of burden-of-proof often enters the theism-atheism discussion. And, based on the context, it’s often appropriate.
But perhaps it shouldn’t be.
Christians are not prosecutors, we are witnesses. We are not necessarily meant to prove things. We are meant to be honest about our experiences, sharing what we have heard, seen, and touched concerning the Word of life.
There may be times for proving things, but the majority of times are times for witnessing to things.
Leave the rest up to the lawyers.