What is he teaching us ? Jesus is teaching us that we should not invite someone into our home who we hope will repay us. Whether our intentions are for material things or not. We should invite someone in who needs us and cannot repay us for our actions. We must do good for people without everyone knowing, for we will get repaid by God.
We can relate to this parable because when we are in school or work settings we usually have someone we look up to. We respect them and want to fulfill their requests. Yet, when someone who maybe isn't someone we like or someone we find weird asks us for something we deny them. We do this because they can't give us the status we want.