Yes, non-Orthodox Jews can become Orthodox by becoming more observant. Non-Jews can become Orthodox Jews through Orthodox conversion.
Talk to a Greek Orthodox Priest about it.
St. Barnabas was not a monk.
Yes. he became a monk after he left his palace.
it usually dependents on what religion you are talking about if it is catholic only a man can become a monk.
Yes
Yes. he became a monk after he left his palace.
No, you do not.
No, the Greek Orthodox church is a part of the Eastern Orthodox Churches.
He never wanted to be a monk.
Erasmus did not become a priest. He became a monk. There is a great difference. An 11 year old child could become a monk if a relative took his vows for him. Erasmus did not become a priest. He became a monk. There is a great difference. An 11 year old child could become a monk if a relative took his vows for him.
There is no fee payable to become a member of the Orthodox Church. Some parishes in the USA have adopted a practice of charging a fee to become a member of a Parish, but this is not compulsory. However, anyone can attend an Orthodox church without paying anything.