I have found a competent article "What is Frisian" by a Frisian native, who is a specialist in languages as well. I gave the link already in a comment, but Mitch asked me to post this as an answer.
The website has some very interesting word chains in Frisian, Dutch, German, and English such as
Frisian English Dutch German
dei day dag Tag
rein rain regen Regen
wei way weg Weg
neil nail nagel Nagel
There are other similar tables on the page, What is Frisian?
Here are some Old East Frisian texts. The navigation from one text to another is a bit cumbersome, the whole website is cumbersome. Use the little square with the yellow arrow. Translations are not given, a pity. Corpus of Old East Frisian Texts
The link does not work like I thought. One can find the Frisian texts, but it's a matter of luck.
It's easier to Google for "old Frisian texts" and choose Titus Texts.
Another interesting link. https://www.fryske-akademy.nl/en/taalweb/
I found the sentence: Hawwe jo fragen? - Have you questions? (German Fragen means questions.)
--- Here's a Frisian poem translated in English. The first line is cited below.
Lyk az Gods sinne weiet uus wrâld oerschijnt;
Like as God's sun sweetly our world o'ershines;
--- Added:
Low German, spoken in the North of Germany beside Standard German, is also very similar to English.
Below I give a story about a young woman who had lost her capacity to speak when her mother died in an accident. The story is in Low German and there is a translation in Standard German.
I have listed all words of the first section that have a close connection with English. I gave the word in Low German, in English, and in German.
Door there da - Dochter daughter Tochter - dat that dass - jung young jung - hör her sie (personal pronoun, accusative) - deen do tun - wenn when wenn - weren were waren - hör Nam her name ihr Name -weer was war - se she sie - blau blue blau - grot great gross - Ogen eyes Augen - Hoor hair Haar/Haare - wat what was
http://www.plattdeutsche-geschichten.de/geschi31.html