Isaiah 7:9
And the head of Ephraim is Samaria, and the head of Samaria is Remaliah’s son. If ye will not believe, surely ye shall not be established. And the head of Ephraim is Samaria, and the head of Samaria is Remaliah’s son. If ye will not believe, surely ye shall not be established.
The message was addressed to Ahaz and the people of Judah when Syria and Ephraim had allied together against them. It promised that the hostile alliance formed against Judah would fail and would not succeed. Both of the opposing kingdoms themselves would soon be brought to an end.
Judah's security depended entirely on believing the word of the Lord. If they would not believe and trust that word, they would not be established and firmly secured. The call was therefore to trust in God rather than give way to fear.
Isaiah 7 is to be read together with warnings against backsliding and refusing to return. It belongs with warnings against trusting lying words and a false peace. It stands alongside the call to amend ways and to execute judgment. It is joined to the call to obey God's voice and to listen diligently so that the soul may live under the everlasting covenant.