Psalm 19:1-3 KJV
The heavens declare the glory of God; and the firmament sheweth his handywork. [2] Day unto day uttereth speech, and night unto night sheweth knowledge. [3] There is no speech nor language, where their voice is not heard.
Romans 10:9-10 KJV
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. [10] For with the heart man believeth unto righteousness; and with the mouth confession is made unto salvation.
Romans 10:13-15 KJV
For whosoever shall call upon the name of the Lord shall be saved. [14] How then shall they call on him in whom they have not believed? and how shall they believe in him of whom they have not heard? and how shall they hear without a preacher? [15] And how shall they preach, except they be sent? as it is written, How beautiful are the feet of them that preach the gospel of peace, and bring glad tidings of good things!