en_tn/act/17/03.md

He was opening the Scriptures

possible meanings are 1) "Paul was explaining the scriptures clearly so that the people were able to understand what he was teaching" or 2) "Paul was opening the book or scroll of Scriptures"

it was necessary

"it was part of the plan" or "it had to happen that way".

to rise again

"to come back to life"

the jews were persuaded

"the Jews were convinced" or "the Jews were won over"

and joined Paul

"and became associated with Paul"

the devout Greeks

those who worship God but have not converted to Judaism through circumcision.

a great crowd

"a large crowd"