I did not say it cost nothing to become a Christian. There IS a cost involved in becoming a Christian and faithfully remaining one.
Simply because a cost is involved does not mean one is earning the free gift.
Last summer (or two) ago a local restaurant offered free ice cream cones on a certain day between certain hours. They did not owe anyone a ice cream cones, so we can say they were offering these free gifts out of their good grace.
Yet to get a free ice cream cone one had to meet the condition, a work, in going to that restaurant and place an order for one. Yet that work in going to the restaurant did not earn the free.
I did not meet the necessary conditions in going and placing an order, so I did not get a free ice cream cone.
If I had met the condition in going and placing an order, then it would have cost me something in time, gasoline and wear and tear on my vehicle, etc., but the ice cream cone was still free, they would not have charged me anything for it.
Unless, until faith only proponents learn these simple facts, they can never have a correct understanding of Bible salvation.