Maybe true because our Lord Jesus Christ said if we want to be His disciple for us to deny self take up our cross and follow Him.
Self competes with following Christ. The apostle Paul in his early life has to fight with himself. He said the things he need to do that he do not.
But the Bible does not teach to harm ourselves but for us to submit to God, resist the devil and he(the devil ) will flee from us.
The Bible also teach that we are crucified with Christ and so we are to be alive with Christ too.
Some of us may have disability or disabilities that make us frustrated sometimes but even our Lord had to suffer on the cross. Yes at some point the physical have power over the spirit but in the resurrection there is no grave to keep our body down as a song say.
But self need not be on the throne of our life but let God dwell in our hearts, minds, souls and spirits. Let us abide in Christ and He will abide in us.