I was watching a video with Tim Keller, John Piper, and D.A. Carson about the Trinity which is quite insightful and good: http://thegospelcoalition.org/videos/44935725
I remembered on a Sunday school, this question was asked "would you stand up and die defending the truth of the Trinity?". It's interesting because the bible does not explicitly state the term "Trinity", and perhaps not many people think that the Trinity is one of those fundamental truths that we should defend like the death and resurrection of Jesus, salvation by grace through faith, or the authority of Scripture. Also, it is really hard to comprehend the Trinity.
But I think the Trinity is on-par in importance.
First of all, we are to grow in learning more about the God who we worship. So the better we know of who God is, the more accurate our understanding of Him is, the more accurate our worship towards the true God is. For example, we all know God is love, but not many know that God is wrathful. So people who lack understanding in the latter, will worship God because He is loving but will not comprehend why the cross of Christ was necessarily for our salvation, and not comprehend that the consequence of our sins is death. Having knowledge of both aspects of God (love and wrath), we can understand that His grace is actually a couple of magnitude larger than we thought, and we will realize that there is nothing else that we can do but worship Him.
The point I want to emphasize is the relationship among the persons of the Trinity (Father, Son, Spirit). Tim Keller in his "Reasons for God" book has a chapter dedicated to the Trinity, and it conveys the beauty of the truth of the Trinity. Basically, he describes it as a "dance", where each person of the Trinity is submitting and glorifying the other members of the Trinity, non-stop. There are examples in John 16-18, where Jesus submits to the Father, or when talks about the Spirit will glorify Christ. Also the statement of "God is love" is profound. Because if God was just one person, then when we said "God is love", he can only love Himself, since love requires more than one member. So the fact that our God is three persons, the statement of "God is love" makes sense because the constant selfless act of glorying one another for each person of the Trinity is the essence of God's love.
Since God loves us first, we can also love Him and love our brothers and sisters. And by understanding the love within the Trinity, we can learn how to love one another by being selfless, gracious, submitting towards one another. God is so good.
