The absolute perfection of Jehovah God could never be a part of any imperfection. All humans are terribly imperfect creatures. None of us are perfect. How can these two sides get together to communicate?
That is the purpose of Jesus, appointed as the Mediator between perfect God and imperfect humanity. There is no human who could fulfill that role. So no clergy need try. This is why Paul at 1 Timothy 2:5-6 wrote, "For there is one God, and one mediator between God and men, a man, Christ Jesus, 6 who gave himself a corresponding ransom for all—[this is] what is to be witnessed to at its own particular times."
By addressing prayers and all things to God by way of going through Jesus, as our Mediator, we can be assured Jehovah God will hear our prayers and our needs.