And this gospel of the kingdom shall be preached in all the world for a witness unto all nations; and then shall the end come. Matthew 24:14

PREACH, v.i. [L. proeco, a crier; precor.]
PREACH, v.t. To proclaim; to publish in religious discourses.

To discourse on the gospel way of salvation and exhort to repentance; to discourse on evangelical truths and exhort to a belief of them and acceptance of the terms of salvation. To preach the Lord Jesus Christ and him crucified, to announce Jesus Christ as the only Savior, and his atonement as the only ground of acceptance with God. (ref. Webster's 1828 Dictionary)

What I tell you in darkness, that speak ye in light: and what ye hear in the ear, that preach ye upon the housetops.

And fear not them which kill the body, but are not able to kill the soul: but rather fear him which is able to destroy both soul and body in hell.

Matthew 10:27-28