Sampson responded to a Christian Post open letter to the worship leader from columnist Michael Brown, entitled "Reaching out to a Hillsong leader who is renouncing his faith." In it Brown said he prays Sampson "would have the integrity of heart to seek the truth earnestly, with humility and passion, and that all others with questions will put those questions on the table."
After emphasising he truly wants answers to his questions, Sampson admitted he's "struggling with many parts of the belief system that seem so incoherent with common human morality."
"If most of humankind had a choice, would we not rid the world of the scourge of cancer? Or sickness and disease? Why doesn't God do such a thing? Of course there is an answer to this question, but the majority of a typical Christian's life is not spent considering these things," he wrote. "Questions such as these remain in the too hard basket."
The artist, who has been with the worship team at Hillsong since he was 16, clarified he wouldn't say he has "renounced" his faith but would say "it's on incredibly shaky ground."
He said: "I have and continue to analyse the arguments of prominent Christian apologists and biblical scholars, and am open minded enough to consider the arguments of atheist debaters and debaters from other religions.
"If the truth is true, it will remain so regardless of my understanding of it. If I search it out, surely it will become even more clearly seen as the truth that it is. Examining a diamond more closely reveals the quality of the diamond. As I am still breathing, I am still learning."
Despite his long history with Hillsong Church, Sampson emphasised his thoughts are his own and do not represent any church, adding, "If anything all I have ever received from Hillsong is support and the opportunity to follow my own mind, and they have always taught what I perceive to be sound Pentecostal doctrine.
"You cannot have well-educated opinions without educating yourself well. This is a window into my thought processes at the present time."
Sampson has worked with Hillsong for over 20 years and is known for writing some of the most popular worship songs, including 'O Praise the Name' and 'King of Majesty' he has also written songs for Delirious.
Stay up to date with the latest news stories from a Christian perspective. Sign up to our daily newsletter and receive more stories like this straight to your inbox every morning.