What is the ruling on a relationship that has developed between a devout young man and woman, where the young man fears it may go against the will of God, knowing that they have never discussed this matter at all?

If the girl is religious and of good character, it is advisable to propose to her and marry her, as the Prophet, peace and blessings be upon him, said: "Nothing is seen for two who love one another like marriage." Avoid talking to her or confessing your feelings to her, as this is from the steps of Satan. Perform the Istikhara prayer before proposing.