Acts 10 is the story of Cornelius and Peter. Peter, as a devout Jew, had little sympathy for Gentiles. Cornelius, though a Gentile, was a devout man who feared God. In a dramatic fashion, God brings these two men together, exposing and insisting that Peter's thinking be changed.
It is appropriate to question whether the story in Acts 10 applies to our stance toward folks who do good but have not made a profession of faith. Does the story in Acts 10 relate to often spoken condemnations of modern day Jews, or Muslims, or Hindus?
Do not accept what I am about to say without asking these questions.
But it seems to me that the application of Acts 10 in our lives may be to stop the condemnation of others and expand our understand of those for whom God cares. Let us be a voice in contemporary Christianity which repeats the words God speaks to Peter in Acts 10 - "What God has made clean, you must not call profane."