I think this would be something for another thread. But the short answer is that these symbols are used repeatedly throughout scripture as judgment figures to show that God was about to bring judgment and destruction upon some particular nation. In the case of Matt. 24 that nation was Israel. But that should be for another thread. Let us not hijack this thread to pursue this.
The bottom line though is that these things that we see, we know them. We see them immediately when we study scripture. Others may not see them. We can try to show them what we see, but if they cannot see them, then there is no way to convince them.
Luk_8:10 And he said, Unto you it is given to know the mysteries of the kingdom of God: but to others in parables; that seeing they might not see, and hearing they might not understand.