Improve the bracketed part of the sentence. It is dangerous and harmful to be guided in our life?s course by hatreds and aversions, for they are wasteful of energy and limit and twist the mind, and prevent it (to perceiving) the truth.
The Euro has been in use in Greece since January the 1st, 2002. So, now Euro (?) is the official currency of Greece. Before that date, the currency that was used in Greece was the drachma.