Can we write conditional sentences in two separate sentences?
Yes, you can, by changing the "if" clause into a statement of fact. While the sentence fragment is ungrammatical (as Jacob noted in his answer), you can reconstruct the concepts into two complete sentences by rephrasing the first sentence. Here is just one possibility.
Parents need to teach children how to face difficulties and how to obviate problems through hard work. Then their children will be more successful persons in the future.
The use of "obviate" seems a bit too formal for this sentence and its topic, although your usage of it is perfectly correct. I would choose to use "prevent" instead. For those who may not be familiar with the word, here is the extended definition of "obviate" from Merriam-Webster, along with some close synonyms.
Obviate derives from Late Latin obviare (meaning "to meet or withstand") and Latin obviam, which means "in the way" and is also an ancestor of our adjective "obvious." "Obviate" has a number of synonyms in English, including "prevent," "preclude," and "avert"; all of these words can mean to hinder or stop something. When you prevent or preclude something, you put up an insurmountable obstacle. In addition, "preclude" often implies that a degree of chance was involved in stopping an event. "Obviate" generally suggests the use of intelligence or forethought to ward off trouble. "Avert" always implies that a bad situation has been anticipated and prevented or deflected by the application of immediate and effective means.
For more information about conditional sentences and their structures, please see http://www.edufind.com/english-grammar/conditional/
This was a good question. I hope my answer is helpful.