Developers and Testers are always at the opposite spectrum, it is because of their combined effort that the product as an end result is supposedly robust and efficiently without bugs. The quality of the product is determined by the testers, you have to understand and know about everything.
With new testing methods and tools, it is the duty of the tester to keep him/herself updated to the latest trends. Read the following article, it definitely will give you knowledge of what to read. But application of the knowledge is a must.