Not able to use copy method on Range(Cells(n,n)) on VBA

Any ideas on why the following works fine:

Sheets("dados").Range("A2:A4").Copy Destination:=Sheets("Resultado").Range("A2:A4")

While this doesn't?

Sheets("dados").Range(Cells(2, 1), Cells(4, 1)).Copy Destination:=Sheets("Resultado").Range(Cells(2, 1), Cells(4, 1))

I've also made a test just trying to set the font to bold. If I use Range("A2:A4") I can change any sheet even without selecting it. But if I use Range(Cells(2, 1), Cells(4, 1)) it only works if the sheet is selected.

The reason I want to use range with cells arguments is that it is easier to use iterators without having to convert to string.

Thanks a lot!