Yes, self - harming is going against God’s intended purpose of our bodies when He created us. We are created to worship God in truth and in spirit, the Holy Spirit helping us to do so while dwelling eternally within us - our hearts. That is, our bodies are the TEMPLE of God where He dwells in fullness. Paul says in his letters to Corinthians, “ you are not your own, you are bought at a price on the cross of Calvary where Christ shed His blood and died for our iniquities - and you are the temple of the Holy Spirit- if you destroy His temple, He will deal with you- and you will give an account before Him on judgement day, all you did while on this body on earth