If you are listening to two sources of information and if you want to decide which source of information is correct to what extent then you need to listen to both opposite sources of information and try to identify the common information that both sources are presenting to you so that would be the area where you could use for yourself to believe in something and also stay the conversation in the direction so the rest of information where the either parties are saying maybe highly polluted by their own partialities and biases.
*Do read the Disclaimer