In Acts 16:26-31 we read, “Suddenly there was a great earthquake, so that the foundations of the prison were shaken; and immediately all the doors were opened and everyone’s chains were loosed. And the keeper of the prison, awaking from sleep and seeing the prison doors open, supposing the prisoners had fled, drew his sword and was about to kill himself. But Paul called with a loud voice, saying, ‘Do yourself no harm, for we are all here.’ Then he called for a light, ran in, and fell down trembling before Paul and Silas. And he brought them out and said, ‘Sirs, what must I do to be saved?’ So they said, ‘Believe on the Lord Jesus Christ, and you will be saved, you and your household.’” The people of the “faith only” doctrine want to stop right here and go no farther in the reading.
But why stop on verse 31? There is more to it than this. The jailer had asked the question in verse 30, "Sirs, what must I do to be saved?" Let's also look at the next three verses, which say, "Then they spoke the word of the Lord to him and to all who were in his house. And he took them the same hour of the night and washed their stripes. And immediately he and all his family were baptized. Now when he had brought them into his house, he set food before them; and he rejoiced, having believed in God with all his household" (Acts 16:32-34).
Notice verse 32 says they "spoke the word of the Lord to him and to all who were in his house." Why? So they could believe. Before a person can be saved, he must first believe. But does belief alone save him? Are people saved when they only believe? What does the Bible say? In John 12:42-43 we read, "Nevertheless even among the rulers many believed on Him, but because of the Pharisees they did not confess Him, lest they should be put out of the synagogue; for they loved the praise of men more than the praise of God." Were these people saved? They believed, but they wouldn’t confess Him. Jesus says in Matthew 10:32-33, "Therefore whoever confesses Me before men, him I will also confess before My Father who is in heaven. But whoever denies Me before men, him I will also deny before My Father who is in heaven." A person will be lost if he is ashamed to confess Jesus before men.
Then we also read in James 2:19, "You believe there is one God. You do well, even the devils believe and tremble." Are the devils going to go to Heaven because they believe and even tremble? I think not. If this is all that is required to be saved, then the devils are saved and will be in Heaven also.
Next notice the first part of verse 33 which says, "And he took them the same hour of the night and washed their stripes". This showed that he had repented, because Jesus says, "Unless you repent you shall all likewise perish" (Luke 13:3). One cannot be saved unless he repents.
Next notice the second half of verse 33 which says, "And immediately he and all his family were baptized". Notice the Bible says they were immediately baptized. Why? Why were they immediately baptized? Why didn't the church at Philippi first take a vote on them, to first see if they were worthy of their salvation, and then wait a month to baptize them (but not to be saved), but as an initiation ceremony to add them to and to join their particular denomination?
Notice after he was baptized, verse 34 says, “and he rejoiced, having believed in God with all his household". His rejoicing came after he was baptized and was saved, not before.