Irish and the Greek alphabets have been proved to be the same

This quote is from 33rd Degree Freemason and Knight, Sir Godfrey Higgins from his book Celtic Druids:

The reader will not forget that the Irish and the Greek alphabets have been proved to be the same, the truth of which will be much more clearly shewn by and by.

I am well aware that these etymologies maybe said to be far-fetched, but they must be considered in conjunction with the other circumstances. And I must beg my reader to suspend his judgment till he has seen the whole of my work, particularly the Sixth Chapter.

All these words and ideas, too, are evidently derived from the word Ieue (so absurdly written Jehovah) of the Jews and Christians, corrupted and debased in every manner that human ingenuity could conceive.

But the Christians have no right to complain of the Heathens for having stolen their God Jehovah.

They have made reprisals, and have stolen ten times as much from the Heathens. They have stolen saints by scores.

Half the saints in the Romish calendar are Heathen Gods.

By Sir Godfrey Higgins – The Celtic Druids