Why Declare? Because the gospel is an announcement, not an advertisement. Psalm 96:3 (NKJV) — 3 Declare His glory among the nations, His wonders among all peoples.
What to Declare? The gospel of Christ is true and transformative for all people who believe. Hebrews 7:25 (NKJV) — 25 Therefore He is also able to save to the uttermost those who come to God through Him.
Where to Declare? From Australia to Asia Pacific and the farthest reaches of the planet. Acts 1:8 (NKJV) — 8 You shall be witnesses to Me in Jerusalem, and in all Judea and Samaria, and to the end of the earth.”