>> Morality is written on our hearts
Existence is intrinsically ‘evil’. But your metaphor describes the intangible means through which we deform it into something meaningful — something ‘Godly’.
That is exactly what the scriptures teach us. And, btw, Christianity is the only religion to do so. Christianity (accurate doctrine) states that we are by nature evil. All other religions (and to be fair-some poorly educated Christians) state a person can reach a higher plain by being and doing well. If one were to look into their heart objectively, they would see we are by nature morally evil (unclean).
Morality and spirituality in Christianity has always been connected. The moral (spiritual) code is written on our hearts, but we break it. One can try to keep the Ten Commandments, but they cannot do it. One can try not to lie but eventually they will lie. The tenth commandment says we should not covet, yet we covet. The law is our measurement and reflects how we are incapable of being "moral" people in the perfect sense of the word. To be sure there are levels of morality (spirituality) but then how can we judge someone if they tell a lie verses murdering someone? What if that lie results in murdering someone? Morality is a slippery slope.
Some people have tried to separate spirituality from morality but they can't be separated. Without believing in a God handing down these moral values, morals don't matter. People are free to live their lives in any way they please. Nothing matters. Total anarchy is just the same as a civilized society. Spirituality/morality defines what "good" is.
Some people have tried to say civilization has created moral codes apart from spirituality. Yet every culture, in ever part of the world holds to the same basic moral codes (e.g. everyone knows murder is wrong). Statistically it would be impossible for every civilization to conclude that murder is wrong. Spirituality and morality are one in the same. And, yes, there have been those who believed they can obtain morality through spirituality. That always results in disaster as with the Holy Wars.
If a person does believe that morals are very important, then these morals (spiritual values) came from somewhere apart from us. It would be impossible for us, immoral people, to know what is moral. They had to be given by someone apart from us for a reason. Thus cultures derived religions to explain these moral values. If a person doesn't believe in God (spiritual) then what do they base their morality on?
If we are truthful, we find that we ourselves are incapable of living up to the high standards of the moral values we would like everyone else to follow. They represent how far short we fall.
Given that the Ten Commandments is followed in some form or another in every society on earth, one can only logically conclude that a higher spiritual being has set forth commandments for society's benefit. And, from there, it's not a short leap to recognize we cannot maintain these godly morals. There has only been one person to ever live up to these standards, and it wasn't something our Lord Jesus claimed but others claimed about Him.
One would do well to seek to see if these things are so Christ. If Christ is truly God, He will make Himself know if we seek His face. I became a Christian not by wanting something more but by understanding what I was not.