In our daily life, how do we differentiate between materialistic & spiritualistic?

for example, computer which i use it made of material elements but when i use it for Krishna's service then it becomes spiritual. Or this body is made of material elements but when we use this body in the service of Krishna then it is no longer material body but spiritual.

When we cook we kill plants which is also very sinful but if we cook food for Krishna then it is spiritual. Because of that it calls as "Krishna Consciousness".

You study but when You study for Krishna then it is spiritual.