Are certain Bible verses not meant for us?

I see people quote scripture to bring them peace but I was wondering is certain scripture not meant for us?

For example Deuteronomy 31:8 says “”Do not be afraid or discouraged, for the Lord will personally go ahead of you. He will be with you; he will neither fail you nor abandon you.

Moses was saying this to Joshua in a specific situation yet I see people quote this verse when they are going through hard times. So my question is are certain verses not meant for us?