Do the words Sacred, Divine and Spiritual have any context in Buddhism? Edit: *In our lay following of the path of Dhamma we need an external object of veneration and an external connotation to actions, which gives it a positive meaning, to help us stick to the actions.
Going beyond simple logic, to do good karma and follow the Samma or right way we need something supra-mundane to transcend the mundane as a clear reason to act in that direction.

Such examples can be, experiencing the Sacredness in the Idol of Buddha at an altar in your house.

Having a mental image of the Buddha as a Divine being rather than just another human having achieved Nibbana through life times of practices 

Thinking your path as something supra-mundane which is Spiritual in meaning of it...that something having to do with spirit(non-material aggregate). 

This gives added meaning to your existance thereby adding flavour to otherwise dry following to the prescribed discipline in its entierity.*

I undersatnd that Sacred is something religious, but as form is emptiness,

Can we call Buddha's statue as Sacred?

Buddha is not the body and body is not to be identified with, if by divine we mean Godly: transcending the  experience of mundane reality....same flower different experience.

Buddha in His body, can we call Him Divine? 

As opposed to mundane life of chasing women, money and fame...defining spiritual life as holy life towards Nibbana...knowing that there is no spirit to be found...

Can we call the path of Dhamma as Spiritual path?

OR

Will these terms create mis- understanding about Dhamma?
I don't think we are (nor should we be) looking at sacredness of the idol but rather Buddha's emanation and nature in our own mind. We can find a Buddha in ourselves. That is at least true in context of Mahayana and Vajrayana (emulating Buddha's mind or Deity's mind). In Pure Land however, this gets very Idol-based so sacredness is stressed, on the other hand it's Amidaba Buddha, not Shakyamuni. Zen has tendencies to do the opposite, the story of "cutting off Buddha's head" or famous "kill the Buddha" koan are some examples of desacralisation. With Theravada I do not know but I have seen Thai Theravadins in a temple taking Buddha's sacredness as an idol quite literally, praying and chanting to statue as if to the divine being - at least that was my impression.

Personally, I gravitate towards seeing Buddha as an object of my true self using a specific practise (like certain Sadhana), thus I completely negate sacredness, divinity and refrain from idolising the Buddha in any way. I consider such divine elevation a hinderance and obscuration to be removed in order to realise Selflessness of things and achieve meaningful progress on the path.

Everyone is divine and therefore no one is divine - everyone is the Buddha, we just have to see this capacity.