You can try this Brian

Sub Example1()
   Dim Firstrow As Long
   Dim Lastrow As Long
   Dim Lrow As Long
   Dim CalcMode As Long
   Dim ViewMode As Long

   With Application
       CalcMode = .Calculation
       .Calculation = xlCalculationManual
       .ScreenUpdating = False
   End With

   ViewMode = ActiveWindow.View
   ActiveWindow.View = xlNormalView

   Firstrow = ActiveSheet.UsedRange.Cells(1).Row
   Lastrow = ActiveSheet.UsedRange.Rows.Count + Firstrow - 1

   With ActiveSheet
       .DisplayPageBreaks = False
       For Lrow = Lastrow To Firstrow Step -1

           If IsError(.Cells(Lrow, "A").Value) Then
               'Do nothing, This avoid a error if there is a error in the cell

           ElseIf .Cells(Lrow, "A").Value <> "1" And _
                  .Cells(Lrow, "A").Value <> "2" And _
                  .Cells(Lrow, "A").Value <> "3" And _
                  .Cells(Lrow, "A").Value <> "4" Then .Rows(Lrow).Delete

           End If
       Next
   End With

   ActiveWindow.View = ViewMode
   With Application
       .ScreenUpdating = True
       .Calculation = CalcMode
   End With

End Sub

Dim rng as Range, i as Long, lastrow as Long
On error resume next
 set rng = Columns(1).Specialcells(xlblanks)
 rng.EntireRow.Delete
 set rng = columns(1).Specialcells(xlConstants,xlTextValues)
 rng.Entirerow.Delete
On error go 0
lastrow = cells(rows.count,1).End(xlup).row
for i = lastrow to 1 step -1
 set cell = cells(i,1)
 if isnumeric(cell) then
   if cell>4 or cell < 1 then
     rows(i).Delete
   end if
 else
    rows(i).delete
 end if
Next

Untested pseudocode.