Purgatory denies the finished work of Christ on the cross. At the moment of our death we will either behold the Triune God in glory or spend eternity in hell regretting our disbelief.
"Superstition is always cruel." -- John Calvin
Upon the death of a loved one the priest and church say to the living relative or friend: "Your loved one is suffering in purgatory, you want your loved one to get out of purgatory don't you? Then you must give, give, give and pay, pay, pay for masses, prayers, indulgences, etc... in order to appease God and help them get out." How much is enough to get them out? No one ever knows and no one can ever be sure their loved one is out of purgatory because the money must continue flowing into the coffers of the church.
What a terrible system of fear and terror, fear for the souls of their dead and terror of death for themselves. I know, because this is what I personally experienced but God, in His mercy delivered me from all of this on the basis of the free gift of grace through faith in His Son, the Lord Jesus Christ.