The Lord Jesus said, "The thief comes only to steal, and kill, and destroy; I came that they might have life, and might have it abundantly." (John 10:10) The mission of the enemy, Satan, is to steal, kill, and destroy. All thoughts of suicide, therefore, are from the pit of hell. Anywhere, anytime anyone entertains the thought of killing him- or herself, it is a certainty that the origin of that suggestion is NOT from God, the Author of life.
True, dire difficulties and seemingly insurmountable situations will face us, prompting the enticement to "end it all." The deeper the grief, the more intense the loss, the greater the temptation to consider "the easy way out."
For one who takes God seriously, His sovereignty must be settled, without reservation. To not only acknowledge, but to embrace the absolute rule of God over one's life, is to experience a release and peace incomparable. So much striving and churning in our hearts stems from having never really settled the issue of His sovereignty in creation, in salvation, in all aspects of life. Yet when the heart is melted before His majesty, when the knee is bent in submission to His Lordship without limitations, then come what may... the enemy's fiery darts of self-destruction can be extinguished.