A native of Mississippi, S.G. Posey was the son of a Baptist preacher. He became a Christian as a child, entered the Gospel ministry as a young man and graduated from Southwestern Baptist Theological Seminary in Fort Worth, Texas in 1918.
He served as pastor of churches in Mississippi, Louisiana and Texas until 1947 when he moved to California to head the Department of Religious Education at Golden Gate Baptist Theological Seminary. In addition to his teaching responsibilities Posey served for a brief time as a pastor in Vallejo before becoming pastor of Calvary Baptist Church in Berkeley.
In 1948, he was elected president of the state convention, a position he held until being elected executive secretary of the Convention in November 1950. He began his duties January 1, 1951.
In the January 11, 1951, issue of The California Southern Baptist, Posey wrote the following:
"As I view the task from where I sit today I am made to realize that it is a cooperative task and that I am not only dependent upon our blessed Lord but that I am dependent upon all our pastors, all of our churches, all of our missionaries, and all of our department heads and agencies in all of our work from Fresno to the remotest parts of our great state.
"If I am to accomplish that for which you placed me here, and that which we all believe our blessed Saviour desires to see accomplished in charming, cultured, Christless California, you must help me out there where you are with the best you have for the sake of the Lord Jesus and His glory in California.
"Our slogan in evangelism throughout the territory of the Southern Baptist Convention is ‘Christ is the Answer.' We believe He is the answer for lost men and women; for troubled and careworn Christian men and women; for our nation and our world in every realm of human experience. Do we believe that He is the answer to the problems of progress in the organized life of the Southern Baptist General Convention of California? I believe He is! And I am ready, if I know my heart, to go my length in applying the principles of Christ to our problems and program in California in the Spirit of Christ."
Posey served as pastor of First Baptist Church in Austin, Texas from 1935 to 1944. The church's Web site, in its history of the congregation, reports that "Posey's heart seemed to be set on three things: to bring as many people as possible into a personal experience with God; to keep His people full of the desire to send out missionaries, especially to foreign lands; and to instruct the congregation in the matter of being true Baptists."
It appears Posey did the same for California Southern Baptists. He had a zeal for missions and evangelism.
Posey served as executive secretary for nine years, retiring in 1960. During that time the Convention started 464 churches, founded a children's home, undertook the support of then California Baptist College, adopted Jenness Park as the state convention camp and chartered California Baptist Foundation.
He and his wife, Katiebel, lived in Riverside and were active members of Magnolia Avenue Baptist Church until his death in 1985. In 1984 the state mission offering was named in his honor.
Herb Hollinger, editor of The California Southern Baptist, wrote in a 1986 editorial: "Posey's life certainly reflects what the state missions offering has come to mean... We think Posey would have rejoiced to see the varied activity which the missions offering will assist. Somehow it just sounds like something he would want us to do."