For the sake of (...)
Means roughly "For the sake of" or In order to be able to do (...)
日本に行くために、貯金をしています For the purpose of going to japan, I will save up money.
When usednoun＋, it must go with a の. 発表のために、
As a result of (...)
Generally this one is done in the past tense.
暑いために、誰も来なかった。 As a result of the heat, nobody came.