1 Pet 1:8 ... joy unspeakable..
Strongs G412 aneklaletos unutterable, inexpressible
2 Cor 9:15 ... unspeakable gift....
Strongs G411 anekdiegetos indescribable
2 Cor 12:4 ...unspeakable words...
Strongs G731 arrhetos unutterable on account of its sacredness
from Amplified version
1 Pet 1:8
Without having seen Him, you love Him; though you do not [even] now see Him, you believe in Him and exult and thrill with inexpressible and glorious (triumphant, heavenly) joy.
2 Cor 9:15
Now thanks be to God for His Gift, [precious] beyond telling [His indescribable, inexpressible, free Gift]!
2 Cor 12:4
Was caught up into paradise, and he heard utterances beyond the power of man to put into words, which man is not permitted to utter.