“Letting go” can mean different things. In a highly dogmatic culture, where absolutes of correct doctrine, the permanent truths and goodness are predominant, “letting go” can have certain meanings. That isn’t the culture we live in. The culture in most of the world is highly relativistic, where truth and goodness are mostly subjective. “Your truth can be X, my truth can be Y, anyone can make their own truth, and all truths are created equal”. Our culture is dominated by Values, which are mostly defined by the Media, and mostly obeyed by a conformist society that wants to follow “what’s trending now”.
In Western societies today, “letting go” might mean reading Thomas Aquinas with an open mind. If you dare to teach Thomas in some universities you will be branded a heretic because you aren’t obeying “what’s trending now”. Whether it’s in Science, History, or any other field, it doesn’t go against humility to believe that some doctrines have more of the truth than others. While people can have different tastes in Art, it doesn’t go against humility to believe Mozart might be better than the latest commercial jingle, or that Shakespeare had more truthful insights than the Kardashians. “Letting go” means we should let go of Relativism, let go of “majority rule” for defining “what’s true now”. Letting go means, with Chesterton, giving a “vote” to our ancestors, rather than obeying Huffington Post. One student, alone in the library or chapel, might come to a fuller measure of truth than a whole hive of students over in the dorm.
Mother Theresa was humble, and she also believed she had the fullest possible measure of the Truth, in Catholicism. That did not mean she rejected truths found in Hinduism. Genuine humility does not mean we all can make our truths, together. It means truth is something we can find, gradually, with our mind and heart. The Truth leads you to God and God leads you to Truth.