Compare two sheets and copy new and delete duplicates in excel

I have two sheets named source and solution and I have to perform following activities.

1. Copy new records from source to solution.
2. Update records if rows present in source and have updated data.
3. Delete rows from solutions if rows not present in source file.

I have written following vba code.

Sub processDuplicate()
    Application.ScreenUpdating = False
    'Declare variables
    Dim Sample As String, test As String
    Dim var As Variant, iRow As Long, iRowL As Long, RowsRange As String
    Dim Row As Long, FoundDup As Range, SalesSampleOrderClmn As Variant
    test = "test"
    Sample = "Sample"

    Dim CountTempNoDup As Integer
    Dim CountTempDup As Integer

    SalesSampleOrderClmn = Application.Match("Sales", Sheets(Sample).Rows(1), 0)
    Debug.Print SalesSampleOrderClmn

       'Set up the count as the number of filled rows in the first column of Sheet1.
       iRowL = Worksheets(Sample).Cells(Rows.count, SalesSampleOrderClmn).End(xlUp).Row
        Debug.Print iRowL
       'Cycle through all the cells in that column:
       For iRow = 2 To iRowL
       'Call subRemoveNotRequiredRows(TempData, SaleSamples)
       '(CompareFrom As String, DeleteFrom As String)
          Set FoundDup = Worksheets(test).Range("D:D").Find(Cells(iRow, SalesSampleOrderClmn), LookIn:=xlValues, lookat:=xlWhole)

        If FoundDup Is Nothing Then
            CountTempNoDup = CountTempNoDup + 1
            Worksheets(Sample).Cells(Row, ColumnNumber).EntireRow.Delete
        Else:
           CountTempDup = CountTempDup + 1
           RowsRange = "A" & iRow & ":M" & iRow
             Worksheets(test).Range(RowsRange).Copy Worksheets(Sample).Range(RowsRange)
             Worksheets(test).Cells(iRow, SalesSampleOrderClmn).EntireRow.Delete
        End If
       Next iRow
       Debug.Print CountTempNoDup; "No Dup"
       Debug.Print CountTempDup; "Dup"
    'Application.ScreenUpdating = True
    Worksheets(test).Rows(1).EntireRow.Delete
    Worksheets(test).UsedRange.Copy
 'Sheets(Test).Copy After:=Worksheets(Sample).Cells(Rows.count, 1).End(xlUp)
    Worksheets(Sample).Cells(Rows.count, 1).End(xlUp).Offset(1, 0).PasteSpecial xlPasteValues
    Application.CutCopyMode = False
    Worksheets(test).Delete
End Sub

I'm facing performance issues in excel and I need help to increase performance and its correctness.

I have one problem with deleting entire row. It's not deleting entire row on till column L.

Worksheets(Sample).Cells(Row, ColumnNumber).EntireRow.Delete