Contradiction with Romans 12:19
Whereas Amos 3:8 emphasizes responding once the Lord has spoken, Romans 12:19 advises believers to leave room for God's wrath and not to take action themselves.
Romans 12:19: Dearly beloved, avenge not yourselves, but [rather] give place unto wrath: for it is written, Vengeance [is] mine; I will repay, saith the Lord.
Contradiction with Isaiah 31:4
Unlike Amos 3:8 which suggests proactivity upon hearing God's voice, Isaiah 31:4 implies a quiet, confident watching where the Lord remains unperturbed by external noise, suggesting inaction.
Isaiah 31:4: For thus hath the LORD spoken unto me, Like as the lion and the young lion roaring on his prey, when a multitude of shepherds is called forth against him, [he] will not be afraid of their voice, nor abase himself for the noise of them: so shall the LORD of hosts come down to fight for mount Zion, and for the hill thereof. [noise: or, multitude]