Passions are like some hard [dark] substances that, standing in the midst between the light and vision, prevent the latter from discerning the difference of things.
St. Isaac the Syrian Homily 66
There are other factors too that St. Isaac mentions affecting our ability to develop the knowledge of God. A weak will, the lack of a spiritual father or mother, a disposition (temperament or personality) not suited for spiritual pursuit. None of these are unchangeable conditions. God’s in the miracle business. But we all have to begin where we are, with the limited ability and Grace we have, to seek to know, to long to know, to strive to give our lives to God. If we do our part, God will take care of the rest. If we follow what we know, maybe God will reveal to us some of what we do not know.