I recently read that the idea of eternal punishment came about “because of a preconceived, unbiblical notion that the soul is immortal (see 1 Tim. 6:15-16). We have read eternal torment into the Scriptures when it was never intended for mankind. Hell was created for Satan and his Angels, not for Mankind and it is Satan and his demonic hordes who will be consigned to Hell and its torments eternally.” Do you believe 1 Tim. 6:15-16 actually means mans soul is not immortal and that it could be destroyed after serving a period of time in Hell?
This is a very weak argument. 1 Tim 6:15-16 says that only God is immortal, which simply means that he will never die. In 1 Cor. 15:53 Paul, the same writer, said that at the rapture/ resurrection all believers will become immortal. Also in Matt. 25:41 Jesus said that after the so-called sheep and goat judgment, the goats (unbelievers) will be sent into the eternal fire prepared for the devil and his angels. So there will be humans there, too.
In 2 Thes. 1:9 Paul had already written that unbelievers will be punished with everlasting destruction. That literally means destruction that never ends. The same Greek word is used in the phrase everlasting life. It also means eternal, or without end. Put it all together and you realize that both believers and unbelievers will exist forever. So the question is not whether we have eternal life but how we will spend eternity.