1Ti says that God alone has life in Himself, we do not, but that is not saying we were not created by Him to live on after these bodies die. We do not have life within ourselves, but it is entirely possible that God could create us in such a way as our soul/spirit live on after our bodies are gone. God alone then able to destroy the soul in Hell. Part of us is going somewhere, one way or the other, after our mortal bodies die. Matt 10:28 just says God is able to destroy the soul, not that He will in regards to punishment not being everlasting. Everlasting punishment would be the destruction of the soul, perpetually.