1. B.B. left the church because his religious interests were more about the music and entertainment factors than Jesus Christ Himself. It is not too surprising that one who was never a disciple would seek to liberate himself from the seemingly constricting requirements of real devotion to the Lord. Hip sounding music easily won out when placed next to the way of the cross.
2. B.B. left a church environment that was (at least in his perception) legalistic and hypocritical. Did he even hear the Gospel in the Southern-cultured, Americanized "evangelical" Baptist and Pentecostal churches he attended? One wonders. Churchy folk certainly did not hide their condemnation of the "blues" musical style, nor of the beer drinking and dancing that often accompanied it. However, King said many church members secretly loved the music!
In short, we are reminded that there is nothing more detrimental to the reputation and health of the local church than unconverted, legalistic, religious hypocrites on the one hand, and the failure to aim for genuine conversion and disciple-making through faithful Gospel witness on the other.
And we might imagine that Reformed believers would have embraced the beer and the music (and perhaps even the dancing--all in tasteful moderation, of course), recognizing these as God's good gifts to be enjoyed, while at the same time holding forth the potent light of the Gospel and calling sinners to repentance and true discipleship.
May our great and gracious God help us not to repeat the errors of a church culture gone wrong in the Deep South of long ago. And today.
We can thank God for Mr. King's amazing talents, and hope in earnest that he did not die unconverted.