You could use On Error Resume Next
then there is no need to loop through all the sheets in the workbook.
With On Error Resume Next
the errors are not propagated, but are suppressed instead. So here when the sheets does't exist or when for any reason can't be deleted, nothing happens. It is like when you would say : delete this sheets, and if it fails I don't care. Excel is supposed to find the sheet, you will not do any searching.
Note: When the workbook would contain only those two sheets, then only the first sheet will be deleted.
Dim book
Dim sht as Worksheet
set book= Workbooks("SomeBook.xlsx")
On Error Resume Next
Application.DisplayAlerts=False
Set sht = book.Worksheets("ID Sheet")
sht.Delete
Set sht = book.Worksheets("Summary")
sht.Delete
Application.DisplayAlerts=True
On Error GoTo 0