Can I lose my salvation by committing some horrible sin and casting myself out?
No. A believer cannot cast himself out of the body of Christ by committing a horrible sin, because we are totally under the control and power of the sovereign God, and nobody can supersede His power. Nothing can separate us from the love of God.
Les explains that when someone claimed he could cast himself out of salvation by committing some horrible sin, the answer is that you cannot touch yourself so far as being in that position in the body of Christ any more than someone else can. Believers are totally under the control and power of the sovereign God, and nobody can supersede His power. Paul’s closing verses in Romans 8 are like the crescendo of a great orchestra, building until he declares that nothing can separate us from the love of Christ and the love of God.