You should have whomever is helping you with the vesting (title) explain that to your husband.
In most cases property owned (BTW this is not legal advice) before a marriage remains the property of that party. Claims can be made if BOTH parties are making the mortgage payment. If you have concerns about this an attorney is the only way to really protect your interests.
Sometimes an attorney can analyze the purpose behind your wishes and explain them in a way that will put your husband at ease..
For example, one perspective might be:
You married late in life, maybe after a prior marriage.
You purchased the home many years ago and have a lot of equity.
You finally found the right man, you want to provide for him, to be equal partners.
He is willing to pay his share of the mortgage, and is okay with you retaining ownership. You could write a will that gives him a "life estate" in the event of your death. If you do have other heirs, this would allow him to live in the property should you die before him, and after his death the property would pass on to your heirs.
A probate attorney might even be better if you are thinking along these lines.