Acts 5

Verse 16: Crowds gathered also from the towns around Jerusalem, bringing their sick and those tormented by evil spirits, and all of them were healed.

Why doesn't that happen now? Do we simply not have the faith?
What would happen if there where some some people who truly had the gift of healing and if people believed that God would heal them if the sick and the lame went to them and every single person was healed?

I have never seen that happen. Why? I have seen people go to healing services and not get healed. Did they lack faith? Is mass healings something that God doesn't do anymore?