Jeffrey D. Lambin,  Presidentsident

Jeffrey Lambin serves as the President of Sierra Theological Seminary and teaches in both the New Testament and Biblical Studies departments. After graduating from the University of Nevada, Reno, he had a desire to study more of the Bible in a structured environment. This lead him to further graduate studies at The Master's Seminary where he planned on earning his M.Div. and then departing to serve in a pastoral role. A turning point occurred for Jeff when he took a class on New Testament interpretation causing him to extend his studies for a second degree. With a New Testament emphasis, he desired to bring, in some small way, a faithful scholarly voice to the academic realm. The result of this desire, combined with the prompting and support of Michael Butler, was the founding of Sierra Theological Seminary.  

Jeff held several pastoral internships in the years prior to STS, the most recent being at Calvary Church in Burbank, CA. Jeff enjoys reading, shooting sports, and work around the house. He has been married to his wife Christa since February of 2012, and they have two daughter soon to be adopted in the Fall of 2017.  


  • Th.M., The Master's Seminary, Sun Valley, CA
  • M.Div., The Master's Seminary, Sun Valley, CA.
  • B.A., University of Nevada Reno, NV

Christa Lambin, Professor of Women's Studies

Christa Lambin is the professor of Women's Ministries at STS. She grew up in the Carson Valley as a third generation  "Nevadan".  She also was the third generation to have graduated from the University of Nevada, Reno in December  2011.  Following graduation, she married Jeff Lambin and moved the following summer to Southern California in order for Jeff to begin classes at The Masters Seminary. In 2016, she and Jeff discussed the lack of solid female leaders in the church today. It was then that a desire formed to incorporate training women for ministry alongside of their husbands to help and work with them. This follows in the long line of godly women who learned at the feet of Jesus, just as the men did, and affirms the example modeled by them in Scripture.  Christa's desire is that the wives of the STS students be equipped with their husbands for the work of ministry, as the Lord leads them. Christa has always loved serving in the church nursery, AWANA, Bible Studies, and various childcare ministries. She and Jeff have been married since February 2012. In March of 2015, they became certified foster parents; they had the blessing of caring for twin boys for the first 10 days of their lives, and then they opened their home again to another sibling set: two girls whom they hope and pray to be able to adopt in late 2017. 


  • M.A. in Women's Studies, Calvary Chapel University, San Diego, CA (current)
  • B.A., University of Nevada, Reno,  

Sergio orozco, professor of old testament

Sergio Orozco is professor of Old Testament at Sierra Theological Seminary.  After earning degrees from Cal State Northridge, Sergio strongly desired to serve the church and train men in the Word. This desire caused him to drastically shift his plans from pursuing a career in Physics to studying scripture at The Master's Seminary. Sergio's desire is to have a twofold ministry: training men by teaching at Sierra Theological Seminary and teaching God's people in the local church context. After he completing his M.Div., Sergio will continue his studies at The Master's Seminary in the Th.M program with an Old Testament emphasis. Sergio has served as a Bible study leader at Grace Community Church for the past five years.  When he is not studying or teaching, Sergio enjoys playing the guitar, hiking and going out with his wife, Daniela.  They have been married since 2010 and have two children Calvin and Amelia. 


  • M.Div., The Master's Seminary (current)
  • M.S. California State University, Northridge, CA
  • B.S. California State University, Northridge, CA

NEIL TilLey, board Member

Neil Tilley has served as lay board member of Sierra Theological Seminary since its inception. Since 2001, his ministries have focused on the development of men as leaders of character and fortitude. He is involved in Biblical counseling as well as missions support for the gospel of Christ.  Neil serves in a biovocational capacity and works in Internet Technologies in the Silicon Valley area.


  • M.S. University of California Los Angeles, CA 
  • B.A. University of California, Davis