Why is it necessary to be born again to understand Christ's testimony?

In John 3:3, Jesus emphasizes the necessity of being 'born again' to see and enter the Kingdom of God. This new birth is essential because natural human understanding is clouded by sin and depravity. Only those whom God has quickened—those who have experienced this spiritual regeneration—can perceive the truth of Christ's testimony. This principle is reiterated in 1 John 5:1, highlighting that believing in Jesus as the Christ is an indication of being born of God. Therefore, the work of the Holy Spirit is fundamental to enabling individuals to comprehend and accept the profound truths of God's revelation through Christ.