What is the ruling on a young man continuing to communicate with a girl online to help and encourage her in her studies, and to offer her religious advice, given the fear of each becoming attached to the other, and his current inability to marry?

It is permissible for a man to speak with a non-mahram woman when there is a need and if there is no fear of temptation. However, if feelings begin to develop between you, it is obligatory to cut off the relationship, because nothing equals safety. A woman should seek a righteous sister who can help her in good deeds. It is wrong to endorse someone based on online conversations, as people often present themselves differently from their true selves in such interactions.