Isaiah 7

The last two phrases in verse 9 present a message that God repeats through his word. Paul picked up the call to stand firm and repeats it ten times in his writings. We must allow our faith in God to provide the strength to faith each situation. It does not mean we may not quake but that we remain unmoved while we quake. It seems to me that when we take a stand with God by faith he will fill us with a love for him that will enable us to endure. That is the message that Isaiah gives to Ahaz; don't be move to panic and let God display his power before you.
It took me about 3 minutes to read this chapter.
Stuart