To move beyond materialism is not easy - it is a well-constructed trap. For many (or most) people in the West; it isn't just a matter of 'opening your mind' to other realities; because what we think we want is self-contradictory...
Most people - when pressed - will say (along the lines of ) "I can't believe in the spiritual world without evidence".
By evidence they mean either a vivid personal miracle ('inexplicable' by materialism) - like hearing a voice that they believe to be God telling them something, especially when backed-up by a vision of a being that they are 100% convinced (with zero possibility of error) is an angel, or Jesus or a similar authority; accompanied by an overpowered conviction of the validity of this experience; and that one's memory and verbal expression of the experience is perfectly accurate and complete...
(Hmm, we can already see problems about asking for a miracle, can't we?)
Or else they mean something that official (government-certified, mass media disseminated) 'science' has told them, and that 'everybody' whom they respect (like primary school teachers, or wise people David Attenborough) assures them really is real and objectively true (like CO2-driven Anthropogenic Global Warming, or that one's sex is a choice...).
Yet the fact is that - unless they already have a change-of-consciousness, unless they develop a new way of thinking - these people would not be convinced of the spiritual realm either by a miracle or by science.
Because they would explain-away any miracle in materialist terms (error, coincidence, hallucination, delusion, dishonesty, manipulation etc.); and because science foundationally and by-assumption excludes the spiritual, so must inevitably fail to produce evidence for the spiritual.
Indeed if science did produce evidence for something spiritual - such as telepathy, or near death experiences - it would, by becoming science, cease to be spiritual; and would instead be explained materialistically.
What this 'circularity' of the argument tells us is that materialism is a metaphysical assumption, not the result of evidence.
In modern public (and private) discourse; we have already assumed that reality is material; and we will interpret all possible evidence in that light.
(i.e. Materialism is Not based-on-evidence; instead, materialism determines what counts as evidence.)
Therefore to demand 'evidence' before we will be convinced of the spiritual just makes no sense! It is just a mental trap. It simply ensures that you (and everyone) will remain trapped in materialism - whether it is true or not.
This means the modern person has, in reality, a choice: to remain inside the metaphysical assumption of materialism or not. And if not, he will need to assume a broader reality that includes a spiritual reality.
The one impossible thing is to be 'agnostic' - because there is no ground from-which to be agnostic about this question.
(One could of course change one's mind, back and forth, between materialism and acknowledging the spiritual realm. Indeed this is likely, across a lifespan. Such psychological fluctuations are part of the human mortal condition. But at any moment one is either a materialist or not - and to assert agnosticism as a current situation is an error or dishonest.)
How to choose, and on what grounds? There are just two main ways in which people choose their metaphysics:
1. Unconsciously and passively to absorb one's assumptions from the social environment (from 'other people'), and - because the process is passive and unconscious - to assert the objective factuality of assumptions by denying that they are assumptions, and denying that there exists any choice...
2. To become consciously aware of one's assumptions and to choose them.
One what grounds? This can only be on the basis of expilicit intuitive reflection - choosing what one intuitively knows (from the heart, at the deepest level one is capable of reaching, where knowledge is most solid) to be the truth about the reality of things.
This is another instance that modern life is becoming very simple and dichotomous, and evil is operating by trying to convince us that life is Not simple!
To win, evil simply needs to keep us confused. So far, evil is winning...