If G-d wanted perfection, He would have been perfectly happy sitting on His heavenly throne surrounded by angels or he might have created a man that can’t sin.
But G-d desired something more, something better than perfection. He created this world, and in it placed the most imperfect of beings – humans. G-d understands that we are not perfect, and He loves us for it.
G-d wants to see us striving to improve, persevering against all the obstacles of the world in which we live, and in which He placed us. Nothing G-d does is without reason, and the reason why we are here is to slip up; and to learn and grow from our mistakes.
Yom Kippur is a day given to us to celebrate, to rejoice over all those times that we fail at our mission here in this world, because those failings give us the opportunity to improve, and to grow stronger in our commitment. – R’ Zalman Wolowik