Since the Tower is a higher arcana card, it carries important messages with it, as all higher arcana cards do. And the fact that the image is a tower, we know that it was part of the original tarot decks in use during the 1400s.One might expect that it would carry the number 9 (all tarot cards have a number associated with them except for the court cards), but, in fact, it carries the number 7. A nine indicates the end of an era, followed by a new beginning, which is the general meaning of the Tower. But since the Tower is a 7, it carries a spiritual message, which we call "a Cosmic Intervention." And carries the message of spiritual shake-up.
The Tower card, especially, indicates that the Universe is intervening to shake up the status quo, and this intervention is necessary as part of the general path that the person is travelling.
Thus the "7 card" and especially the Tower, carries with it both "good news" and "bad news." The short-term is stressful and challenging, but the long-term is greatly improved.
A 7 carries the reassurance to have faith in the things that can’t be seen, but nevertheless exist. The number 7 suggests that the seeker must know the ultimate truths. A 7 says that it is only through experience that intellectual and spiritual understanding develops... and faith in the unseen is attained.
Key words include faith, observation, investigation, discrimination, meditation, discovery, knowledge, wisdom, perfection, fear, faithlessness, pessimism, skepticism, doubt, ignorance, and escapism.
Many 7s in a Reading indicate a period of introspection or solitude. They also indicate unlooked-for advantages or gains through things that come unexpectedly. There is no doubt that the Tower is a high stress card. But this stress can lead to a blinding flash of insight, or a moment of truth so overwhelming that there is no way to ignore it.
In any case, it does portend that the usual ways of doing things -- old systems -- are breaking down (or must be broken down) in order to be replaced.
This process can create anxiety as security is questioned and in some cases, destroyed. At its worst, the Tower indicates that when the troubles begin, they will come quickly and illusions are shattered. The good news is that the truth about people and situations are revealed in great clarity.
The card recommends a questioning of previously accepted beliefs. After some major transition, it does give congratulations and suggests that the questioner can feel proud of how issues have been handled. (New Age Directory)