Can I invite my sponsored child for holiday in Hungary?

We appreciate your good intentions, however, we would discourage you to do so. First of all, the travelling costs are quite high (a return flight ticket to DR Congo is at least about 240 000 HUF). Second of all, it is very difficult and complicated to obtain a visa for a Congolese child. In addition, he only speaks French, therefore, you need to know this language so as to be able to communicate with him.
At last, one always has to take into consideration the fact that after the short stay the child has to return to his country. Living in another, more developped environment might bring him a lot of joy and new experience. However, at the same time it might be extremely difficult for him to deal with the culture shock and return to the poor circumstances from which he is coming.
Therefore, we recommend instead that our sponsors travel to Africa, if they have the opportunity, where they can personally visit their sponsored child.