What does Will believe gives him the strength to hold back the Dark at the church doors?

Will believes that his strength to hold back the Dark at the church doors comes from the love and support of his friends and family, as well as his own determination to protect them. He draws on the hope and light they represent, which empowers him to resist the encroaching darkness. This connection to others reinforces his resolve and gives him the courage to stand firm in the face of overwhelming odds.