There are no such people and it is impossible to postpone a belief about something. If it is preached, you either receive it or you don't, there's no 'i'll receive later'.
Scriptures tell us severally that we must receive and hold on. this is just one of them:
1 Cor 15:
1Now, brothers,
I want to remind you of the gospel I preached to you, which you received, and in which you stand firm.
2By this gospel you are saved, if you hold firmly to the word I preached to you. Otherwise, you have believed in vain.
1. The gospel was already preached to them
2. They had already received it and believed it
3. Only if they hold on will they be saved by this Gospel
4. If they don't hold on, they have believed in vain
I see harmony, perseverance and holding on is one and the same thing.