I don't think the parable of tepid water was in our Lords intention nor included in the bible, and it is not part of the traditional interpretation of the Church. It is true that the city of Laodicea was none for its lukewarm water, it was also known for being lax in its ways due to riches.
 
Read the rest of the revelations 3 15-22 and our Lord says clearly "Such as I love, I rebuke and chastise. Be zealous therefore, and do penance."

Following His will half heartedly is of no use. It is one thing to try fervently and fail, but it is another thing to be lax and still expect grace to come. 

Being fervent about the Church's faith and compassionate are not mutually exclusive. Saint Nicholas who gifted many who were poor and destitute also was the same man who punched Arius in the face for being a heretic. He was anything but lukewarm.