To be open-minded is to take a new idea to be true first, in order to try it out in practice, and then let it demonstrate its validity.
Beware of wrestling with, arguing with, or assessing a new idea. If I 'approve' of the new idea, who is the 'I' who has approved of it'? The 'I' could be the ego. That means that the ego has deemed the new idea suitable for assimilation into its bloated system. The ego is like the Borg in 'Star Trek'. Sure, it can assimilate, but what it assimilates is then only superficially recognisable after assimilation. It has lost its substance and purpose. It now serves its new master.
In this way, it's possible to go through the spiritual life, assimilating all manner of new ideas into the ego's system, and be left exactly where you started, just full of spiritual rationalisations for it.
Real open-mindedness is incapable of judgement. It merely accepts, because of the authority of the person offering it. It is entirely at peace. It recognises it does not have the ability to judge. It does not analyse or quarrel because it has no basis for doing so.
Are you open-minded to new ideas, or are you asking your ego whether the new idea can be assimilated into the existing dysfunctional system?