Paul famously says it in Romans 1: 20-21. The essence of the invisible divine has been obvious since the beginning of creation.
Jesus affirms the truth in the countless ways he looks to the obvious and immediate around him for evidence of that which cannot be easily seen by rational animals (men).
If Jesus is dealing specifically with those who are concerned with the ancient written tradition of the Hebrews than he deals with them on their turf.
But more often than turning to the old Hebrew texts he turns to the text that has revealed the invisible kingdom of the divine since the beginning. Whether talking to a Jewish teacher, his disciples, those he encounters in his moments of miracle, or those he talks to in parable he talks to people about this ordinary world and uses it to reveal the invisible kingdom of the divine. It is as if the intangible is accessible through the tangible. What Paul says in Romans 1:20-21 is manifested in the life of Christ himself and his teaching. If one looks closely at the ordinary one will find the extraordinary.
Take the following as easy-at-hand examples and know that a careful survey of the teachings of Jesus would enlarge the list: Jesus employs natural birth, water, bread, seasons, planting, growing, harvesting, bosses and employees, courts and judges, and the list goes on.
According to Jesus the best way to get at the kingdom of the divine is to look closely at what is revealed through the natural world. What is required for the seeing? Purity of heart. “Blessed are the pure in heart, for they will see God.” Good character is the key to clear vision and knowledge not a PhD.
How saturated is the ordinary with the extraordinary? “Ask and you shall receive.” What is the upper limit of insight staring me in the face? Let’s see.
First, let’s focus on clarity of sight and hearing. Clarity is a funny thing. The lack of it will infect even the effort to read the sacred text whether that text be scripture or nature.
Second, let’s be patient while we focus. Woe to he who sets a time limit on cleansing and grows frustrated by the failure of unjust expectations about how long it will take to gain insight.
Third, let’s work at it. Look! Listen! Jesus and indeed Socrates are such models. Socrates, at his trial, in cross-examining Meletus who has brought charges against him, talks about horses and neighbors in order to deal with the trumped up charges of corrupting the youth and believing falsely about the gods. He doesn’t need subtle arguments. If you understand horses and neighbors you will understand how silly Meletus’ charges are.
Jesus is similar. Think about seeds, bread, water, wine, fish, storms, managers, chaff…its all there. It is not the depth of learning, but the depth of character that gives the man power. It is not the PhD but the purity of heart.