If one parent is deceased and the other is remarried, how should the invitation be written? The bride would like to have her deceased mother on the invitation, but should she include her stepmother on the invitation with her father who is giving/paying for the wedding. Should it be "Mr. John Doe" or "Mr. and Mrs. John Doe" request the honour of your presence... This is an issue we would like to be addressed. Thank you for your help!

I think the stepmother should be included if she is married to the father of the bride and is paying for the wedding.
Re: the deceased mother I personally wouldn't put like the invite is from her thou, but mention her name elsewhere? Maybe?