There are always two primarily things, we can do for our relationship with God. The first thing is to spend time with God, praying, worshiping and thanking him, and listening to what he wants to tell us. The second thing is, doing things for God.
Spending time with God, talking to him, and he talking to us, is called a relationship, and in any relationship, there is a conversation. Doing things for God, is doing things for him. There is not a conversations, and there is not listening and speaking, to one another. That is not a relationship, because there is no conversation.
A relationship without a conversation, is dead, and is no relationship at all. If two people do not talk with each other, and do not spend time together, there is not relationship. Spending time together with another person, and talking to, and listening to them, is what defines, and develops relationship.
On the other hand, doing things for God, although important and necessary, is lacking the relationship and conversation part of it, which makes a relationship, to exist and be a relationship.
Of course, doing things for God, is still because of our love for God and still expresses our love for God, but is not a relationship in the full sense of it.
Even Jesus said that Mary has chosen the better part, in comparison to her sister Martha, because Mary was sitting at the feet of Jesus, looking in to his eyes, and listening to what Jesus was saying. Luke 10:38-41
On the other hand, Martha was busy in the kitchen, doing things for God, but not spending time with him. Surely Martha was doing things in the kitchen out of her love for Jesus, to prepare a meal for him and his disciples, but there was not a conversation, and there was not talking to, and listening to each other. So there was not really a relationship.
Relationships is only when two persons spend time with each other, talking and listening to each other, even if they do not anything for each other, just spending time together, and listening and talking. Just sharing with each other. Just loving each other. Love is about relationship, relating to each other, and relationships is about a conversation.