Peter lombard says sacraments bring ""invisible"" grace. why would it be important for humans to have something visible that brings the invisible presence of god? explain.

People mostly believes by seeing .

Explanation:people have curious minds and they work mostly with sight , it is hard to believe truly and beyond reasonable doubt without evidence; maybe that is the reason we have may theories because our curiousity always drives us to find reasons which can be substantiated with evidences.

Miracles are one signs that brings that bit of evidence for religious people that there is indeed a God .

People want to see, they want evidences and they want tangible signs so that they can real say this thing is real and alive .

answer; /// the above statement is (true);