Is the following sentence coherent to a native speaker? or how do you usually say that?
One of the great challenges today is that we often feel untouched by the problems of others.

One of the great challenges of today/ today
One of the great challenges of our age
One of the great challenges of these days
One of the great challenges we are confronted today is that..

or how?

Question

Is the following sentence coherent to a native speaker?  or how do you usually say that?
One of the great challenges today is that we often feel untouched by the problems of others.

One of the great challenges of today/ today
 One of the great challenges of our age 
 One of the great challenges  of these days
 One of the great challenges we are confronted today is that..

or how?

Answer

This is fine: One of the great challenges today is that we often feel untouched by the problems of others.

These are also OK:
One of the great challenges of today
One of the great challenges of our age 
One of the great challenges we are confronted today is that..

This is not:
One of the great challenges of these days (need to leave out "of")

Answer

One of the greatest challenges today is that we often feel untouched by the problems of others.