Train travel from Heathrow to Westerminster Abbey

From Heathrow take the Elizabeth line to Bond Street, then change to the Jubilee line to Westminster

It is easier and just as fast to take the Piccadilly line to Hammersmith or Barons Court then take a few steps across the platform, and take a District line train to Westminster.

This begs the question as to what you are going to do with your luggage before going into Westminster Abbey.

These are the restrictions on taking luggage into the Abbey-

Large items, such as suitcases and large backpacks will not be admitted and there are no luggage facilities at Westminster Abbey.
Excess Baggage Company offers left luggage facilities at Charing Cross and Victoria stations, both within walking distance of the Abbey. See the Excess Baggage Company website for more information. Bags of any size with wheels will not be allowed into the Abbey as they can damage the floor.

Stasher do luggage storage for £4.69 a bag at the Premier Inn Hub Westminster Abbey (on nearby Tothill Street)

Thank you all! I appreciate the responses.