He still has a mind we can relate to, like a child can relate to their parent. If you cared to look into Aquinas’ idea of God you’d find many concrete ideas, but he’s describing the spiritual realm so obviously it’s not as concrete as describing a human person... that’s the whole point.

What’s very concrete is what God has revealed to us historically through his people Israel, and through his son’s incarnation. What the church does is try to take these revelations/projections and through reason map out the source.