When Paul and Silas were in prison they prayed and an earthquake came; and all the doors of the prison were opened including the prisoners bands (Acts 16:25-26).
“And 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.
But Paul cried with a loud voice, saying, ‘Do thyself no harm: for we are all here.’
Then he called for a light, and sprang in, and came trembling, and fell down before Paul and Silas,
And brought them out, and said, ‘Sirs, what must I do to be saved?’
And they said, ‘Believe on the Lord Jesus Christ, and thou shalt be saved, and thy house’” (Acts 16:27-31).
“For God so loved the world, that he gave his only begotten Son, that whosoever believeth in him should not perish, but have everlasting life. For God sent not his Son into the world to condemn the world; but that the world through him might be saved. He that believeth on him is not condemned: but he that believeth not is condemned already, because he hath not believed in the name of the only begotten Son of God” (John 3:16-18).