You will not find any more of these "Death Penalties" in the New Testament, Christians are now under Grace, not the law. You strawman complaints would hold water 2000 years ago, but in these times they are null and void. And even though God killed his own son, the Son laid down his life willingly to achieve forgiveness to all who believe in him. Why did God choose to do things this way ? I do not know, but he did.