When we think of sobriety, what naturally comes to mind is not being intoxicated by a substance (often alcohol). Specifically, we are called not to be drunk with alcohol, but to be filled with the Holy Spirit (Eph. 5:18). Alcohol or any substance has the ability to control us which in turn causes us to lose control. In general, Christians are called to be sober-minded (1 Pet. 1:13). This speaks of the mind regarding anything that leads us into a state of spiritual intoxication. The fruit of the Spirit is self-control. Christians are called to be temperate, we could say level-headed, biblically evaluating all things, clear-minded, sober in spirit.
Randy Smith