Manufacturers always issue an instruction manual with every machine they put on the market. By referring to it we learn how to use it to its utmost potential.
Human beings are the most complicated physical and spiritual entities ever designed and created. Fortunately our Maker also issued us with an instruction manual to refer to, when the going gets tough. That Manuel is the Bible, and Apostle Paul describe it like this: "All Scripture is God-breathed and is useful for teaching, rebuking, correcting and training in righteousness," (2 Tim.3:16)