Please understand that something you think is helpful may not be. You should assume it isn't unless you have specific knowledge of the person involved.
In general, the bereaved don't need platitudes which cheapen their loss or try to fast-forward them through the grieving process. Don't presume to know what the deceased _or_ the bereaved feel or _should_ feel, and don't assume they share/d your beliefs.
Instead of 'comfort and a kind word', try 'comfort' until you are asked for more. Be present for those who are grieving. Offer to help in any way you can if you can, and help when called upon.
Just listening is profoundly useful. Often, they're not really listening to you anyway.