Passing the Civil Service Exam will give you oppurtunity to apply for a government position. There are two classifications in a Civil Service exam, the professional and the sub-professional.
According to the Civil Service Commision, the Career Service Professional and Sub-professional examinations are open to all applicants regardless of educational attainment. Applicants for both levels should (1) be a Filipino citizen, at least 18 years old, and of good moral character; (2) Have no criminal record or have not been convicted by final judgment of an offense or crime involving moral turpitude; (3) Have not been dishonorably discharged from military service or dismissed for cause from any civilian position in the government; and (4) Have not taken the same level of career service examination within three months from last examination taken.
You can check the Civil Service Commission site for more info.
If you're going to take the exam you should be responsible if you want to pass the exam. You can enroll in review centers or you can self-review. You can search in the net for some reviewers but here's a proven exam reviewers that will let you pass the exam: