John 1:18

No one hath ever seen God; the only begotten God, who is in the bosom of the Father, he hath made him known.

John 12:41

These things said Isaiah, because he saw his glory, and spoke of him.

Treasury of Scripture Knowledge

Summary

And when Gideon perceived that he was an angel of the LORD, Gideon said, Alas, O Lord GOD! for because I have seen an angel of the LORD face to face.

Bible References

Because

John 1:18
No one hath ever seen God; the only begotten God, who is in the bosom of the Father, he hath made him known.
John 12:41
These things said Isaiah, because he saw his glory, and spoke of him.