The Presbyterian Church (U.S.A.) office of Theology, Formation and Education maintains a list of resources commemorating remembrances of the 9/11 terror attacks on the World Trade Center in New York and the Pentagon in Washington, D.C.
The materials include resources for liturgy and prayer, education, theology, interfaith, pastoral care and devotions that continue to speak hope, peace and courage to those affected by the tragedy.
From an extensive guide produced for the 10th anniversary commemoration of the attacks, an included prayer reads:
Eternal God, our only hope,
our help in times of trouble:
show nations ways to work out differences.
Do not let threats multiply
or power be used without compassion.
May your will overrule human willfulness,
so that people may agree and settle claims peacefully.
Hold back those who are impulsive,
lest desire for vengeance overwhelm our common welfare.
Bring peace to earth, through Jesus Christ,
the Prince of Peace and Savior of us all.
Amen.
Additional resources, including a hymn and liturgy produced by PC(USA) pastors, are available at the September 11 remembrance page.