Zac Poonen emphasizes the urgent call for believers to overcome sin and live in holy conduct, as highlighted in 2 Peter 3:11-12. He points out that the missing element in today's preaching is the call to overcome, which has been God's message since the fall of man. Poonen reminds us that overcoming is essential for inheriting God's promises, as stated in Revelation 21:7. He encourages believers to live a life that radiates God's glory, just as Jesus did, and to remain faithful with an eternal perspective. The sermon concludes with a powerful reminder that anyone can be an overcomer throughout their life.