It is clear that the way in which Parris eagerly jumps onto the bandwagon of the witch hunts is done out of a desire to increase his own standing and authority in Salem. However, this plan disastrously backfires in Act IV, when Abigail runs off with his savings, and he realises that what she said and what she accused others of must have been all lies. As a result, Parris finds that his actions which have resulted in a short term gain of power have had the long term impact of endangering his life. Note what he reveals to Danforth in Act IV:
Tonight, when I open my door to leave my house--a dagger clattered to the ground. You cannot hang this sort. There is danger for me. I dare not step outside at night!
Even though initially Parris was able to gain power by supporting the witch trials, the long term impact has been to sour his relationship with the people of Salem so that now he is hated and despised. As he comes to realise, he now faces considerable danger for his role in the witch trials.