I was wondering the nuance between those words.
天 seems to have a more mystical flavour (like in the word 天上).
I don't get the nuance between 空/大空 and 地/大地.
土地 seems to be a smaller/more localised land than the other two.
Feel free to edit my post and add any related word that seems relevant.
空 and 大空 both mean the same thing, but 大空 emphases the vastness of the sky. Analogous to that, 地 and 大地 mean the same thing, but 大地 stresses the size of the land/earth.
天 has a nuance of being distant to or above earth and it is the word you would used to contrast against it: 地と天. For that reason, it should not be surprising that it can also mean heaven.
A recommendation for the future: I personally think the goo 類語 dictionary is very great to quickly get an overview over the differences of similar words (I also used them for reference here), see 空(そら)／大空(おおぞら) and 地(ち)／大地(だいち)／土(つち).
