Acts 16:26And suddenly there was a great earthquake, so that the foundations of the prison were shaken: and immediately all the doors were opened, and every one's bands were loosed. 27And the keeper of the prison awaking out of his sleep, and seeing the prison doors open, he drew out his sword, and would have killed himself, supposing that the prisoners had been fled.
28But Paul cried with a loud voice, saying, Do thyself no harm: for we are all here.
29Then he called for a light, and sprang in, and came trembling, and fell down before Paul and Silas,
30And brought them out, and said, Sirs, what must I do to be saved?
31And they said, Believe on the Lord Jesus Christ, and thou shalt be saved, and thy house.
Please note that Paul and Silas didn't say be baptized (although they said it afterwards) receive the gift of the Holy Ghost, partake of the sacrament, receive a priesthood, go to the temple to get endowments, get sealed to his wife for eternity and be a savior on Mt. Zion for his dead ancestors and then would he be saved.
What he said was
BELIEVE and not only would he, the jailor, be saved, but his whole household, too.
Praise be to God
Mac