I think that to be strong for life is to understand more the depth of living. If one is to be strong without understanding that is simply wrong. But to be strong shouldn't be a goal, it just arrives when understanding happens. When the eyes of mind see the threshold of next step, there is no turning back. I come to think today that living spirit is just a bundle of thoughts, feelings and five senses as Buddha once told us thousand years ago.
Without body, spirit has different vibration in human world. For example spirits don't have five senses which means the ability of smell, hear, touch, see and taste do not exist in spiritual world obviously. Probably they have their own special way(ability) to see and communicate with us when it's necessary. And I think necessity comes when energy level is matched to each other. There could be like a formula of photons in mind matter. But the ghost who keep personal emotion can't guide us, because they are the one who need help.
When one life ends, the spirit should let everything go which means every emotions that one think it can't possibly be forgotten should all die. Watching deeply the Intensity of emotion will lead one to understand the constant pattern of rise and fall... And realize how unimportant all kind of angers and sandness. Eventually what remains from all emotions is the layer of strength in true self and that is I think what spirit is after. When humans ask for help from invisible spirits, they can be guided by related spirits but their communication is very limited since humans are so caught up with our own affairs. It's also because spirits are formless energies and there completely different way of being continues. The rule of universe can only be understood by right mind state.
The core of Spirit do not know time and I as a spirit is nothing to do with human 'I' after death therefore I don't exist. There is only a spirit. My mind about human thoughts, feelings and five senses die with body. What will be as 'I' after body dies? Mind of spirit is like the movement of water, clouds or wind. There is no attachment but it stays in tuned with tremendous love. It is focused to be a whole.