This acronym has been used to mock and also used in completely opposite circumstances that a Christian would to reply with wwjd.
It is also a popular song by the band ISMFOF. I-Set-My-Friends-On-Fire.
In a situation where ethics should be used in the making a decision and your are selfish and don't care about other people, then use the phrase "What The Fuck Would Jesus Do?"
When a homeless person asks you for money...blatantly refuse and say "WTFWJD?"