How Was Moses Able to See God's Face?

Why did God say no one could see His face, but the Bible says that Moses spoke face to face with God?

Not so with My servant Moses; he is faithful in all My house. I speak with him face to face, even plainly, and not in dark sayings; and he sees the form (Hebrew word translated as form is "temuwnah," and it means likeness, image) of the LORD. Why then were you not afraid to speak against My servant Moses?"
(Num. 12:7-8)

Speaking to the Lord face to face is a matter of speech. It means that the Lord spoke directly to Moses, and Moses spoke directly back to Him. Moses saw the form, or an image, of God and his back parts, but not His face.

And he said, "I beseech thee, shew me thy glory." And he said, "I will make all my goodness pass before thee, and I will proclaim the name of the LORD before thee; and will be gracious to whom I will be gracious, and will shew mercy on whom I will shew mercy."

And he said, "Thou canst not see my face: for there shall no man see me, and live." And the LORD said, "Behold, there is a place by me, and thou shalt stand upon a rock: And it shall come to pass, while my glory passeth by, that I will put thee in a cleft of the rock, and will cover thee with my hand while I pass by: And I will take away mine hand, and thou shalt see my back parts: but my face shall not be seen."
(Ex. 33:18-23)

For the law was given by Moses, but grace and truth came by Jesus Christ. No man hath seen God at any time, the only begotten Son, which is in the bosom of the Father, he hath declared him.
(John 1:17-18)