Preach the word; be instant in season, out of season; reprove, rebuke, exhort with all longsuffering and doctrine.
Romans 10:9 KJV 1900
That if thou shalt confess with thy mouth the Lord Jesus, and shalt believe in thine heart that God hath raised him from the dead, thou shalt be saved.
Ephesians 2:8 KJV 1900
For by grace are ye saved through faith; and that not of yourselves: it is the gift of God:
Acts 16:31 KJV 1900
And they said, Believe on the Lord Jesus Christ, and thou shalt be saved, and thy house.