Jude has become famous as the patron of the impossible. Simon traditionally has been Jude's partner, and may be considered at least the partner of the patron of the impossible.
What impossible things do Jude and Simon deal with? Because we know so little about these two apostles, it is difficult to answer this question. Jude has one line in the whole Bible. He asked Jesus a stupid question. Jesus had said He would reveal Himself to those who obey and love Him (Jn 14:21). Then Jude asked: "Lord, why is it that You will reveal Yourself to us and not to the world?" (Jn 14:22) The obvious answer is: "Because the world doesn't love Me but you do or will." Jude's question was about divine revelation.
One of the few things we know about Simon was that he was "called the Zealot" (Lk 6:15). This meant he was known as a guerilla — someone who does acts of terrorism and violence to overthrow the government. Imagine how shocked the Zealot was to hear Jesus preach the Sermon on the Mount and be commanded to offer no resistance to injury, turn the other cheek, and love enemies! (Lk 6:27-28; Mt 5:39) What a seeming impossibility!
Jude and Simon may play a special role in helping us accept revelations from God which seem impossible to take. Such revelations might be: "sell your possessions" (Mt 19:21), quit your job (Mt 9:9), refuse to pay taxes for abortion, apologize, admit you're wrong, quit using contraceptives, tithe and give alms, etc. Receive, believe, and do the impossible.