“I don’t know how often that happens but I know of at least one person who explained his desire to give to his wife as a way to strengthen his relationship with Hashem.”
All of our relationships with others should be for the purpose of strengthening our relationship with Hashem. Not that you are using the person – you have to make sure that you are not treating them like a tool to gain Mitzvah credit.
The point is that Hashem wants us to have relationships with others. Everything we do for others is to help us build a relationship with the person. We are trying to build a relationship with the other person because Hashem wants us to build a relationship with them. So it’s not that you are using them – you sincerely want to build a relationship with them. But your sincere desire to build a relationship with them is based on your relationship with Hashem and the fact that you know that He wants you to build relationships with others since this helps create and strengthen your relationship with Hashem. So essentially, all three of the relationships a person is supposed to have (with Hashem, with himself and with others) are supposed to all be intertwined.
I don’t know if I explained that clearly or not. Let me know.