Born and raised in a small town just outside of Marion, Illinois, Dr. Barnett graduated from Marion High School in 1976. He was recruited to play baseball at John A. Logan College, Carterville, Illinois, where he earned his Associate degree in 1978. Two years later, he earned his bachelor's degree in biological science from Southern Illinois University.

Dr. Barnett married his high school sweetheart, Beresa Kelly, in 1979 and then graduated as the father of two girls with honors as the salutatorian of the 1984 class from the University of Missouri School of Optometry. Beresa Kelly, also from Marion, is an interior decorator who owns her own business, Beaux Arts. They have three girls, Tara, Erica, and Taylor.

Dr. Barnett enjoys spending time with his family, going to church, going hunting, fishing, and painting wildlife. He is a dedicated deacon, husband, father, and doctor who has a passion for serving Christ and others.

He earned his bachelor's degree in biological science from Southern Illinois University.