The Godhead Being One

I work at the MTC chatting online with people who have questions about the gospel on Mormon.org. It's an amazing job. But often we get difficult questions from people that I'm not always sure how to answer. 

In everyone's lives they are likely to come across these kind of questions at some point whether it's in our interactions with non members or even members too.

One question that can be hard to answer is why it might seem that even the book of Mormon says that God, Christ and the Holy Ghost are one being as in 2 Nephi 31:21, 

"And now, behold, this is the doctrine of Christ, and the only and true doctrine of the Father, and of the Son, and of the Holy Ghost, which is one God, without end. Amen."

However today I came across a scripture in the Book of Mormon that clarifies Christ and Heavenly Father's relationship. It's in 3 Nephi 19:23. Here Christ will teaching the Nephites teaches them what the unity of the Godhead means and how we can be part of that unity. It says,

"And now Father, I pray unto thee for them, and also for all those who shall believe on their words, that they may believe in me, that I may be in them as thou, Father, art in me, that we may be one."

Here we learn that Christ wants us to be in us as the Father is in him. That we may be one with both Christ and Heavenly Father. As we believe in Christ it allows him to be a part of us. As we move towards him and trust him his doctrine imprints itself on our lives, we want to do what he does, we feel the joy that he does. We become want to live as He lives, just as He lives as the Father lives.

This is a beautiful truth that not only answers a confusion about the godhead but deepens my faith in Christ and my desire to come unto him.