Hi, everyone!!

I have a worksheet that has data in column A and the other in column B. Now
I want a VBA code that would higlight the data in column A if matches with
that in Column B. The code should search the whole A column for a data in B1
then start for B2.
I have a code mentioned below but it takes a long time but it works.
Any can help me for a quick code process?

Private Sub CommandButton1_Click()

Dim I As Integer

Worksheets("Sheet1").Activate
For I = 6 To 877
For J = 6 To 877
If Cells(I, 2).Value = Cells(J, 22).Value Then
Cells(I, 2).Interior.ColorIndex = 3
ElseIf Cells(I, 2).Value = "" Then
Cells(I, 2).Interior.ColorIndex = 4
End If
Next J
Next I
End Sub