The reason he believed this to be the case was because his cultivation technique had been proven not to have been at fault when he easily broke through to the Chaos God realm and his understanding of his body was perfect. The only variables that were not fully accounted for were the Trinity gems that he had merged into his being. He still did not know much about these gems and they could have interacted poorly with his cultivation breakthrough.
The more he analysed the situation, the more he believed that this was the case. He had created his cultivation system, the Akron Dao Path so that its major aim was the pursuit of perfection and in this pursuit, the principles of his systems were clear, one had to first achieve Eternal life while insisting on absolute freedom at all stages.
This would be the beginning to one reaching out for perfection.
There would be more stage before true perfection could be grasped but these two things were a must.