The ultimate action for every human being is happiness.
Getting education, getting married, getting a job, making money, going on vacation, having children, sleeping, eating, hobbies, successful and numerous more is a way for human beings to fulfill their longing for happiness. Faith or religion is not an exception. People can say we truly love God, trust God, seek God but we do all this so that we ourselves can be happy. We trust in a higher being so that our hearts can be filled with happiness.
Yes we human are born selfish. If you observe a two year old child he think he is the king of the world. He wants everything his way and if that does not happen he makes sure the people around gets the message by crying or having a grumpy face. It is our instinct to want for ourselves but in the readings of Plantinga, he urges us to not hope for ourselves only but to extend that hope to other human beings. That is why Jesus is considered a great man. The main reason he came down on earth was because of us, because of others. He did not come down here for his success or reputation but merely for the love of his children and to save them. The sacrificing love of Jesus compels us to do the same. That is why our goal on earth is to be like Jesus because there is no other human being that lived on the face of the earth who has been perfectly following God’s will. Jesus Christ is the perfect role model how Christians should live their time on this earth.
I have the right to happiness, but only in a Jesus like way that God would be glorified through my pursuit of it.