Lately I've become a bit more selective of when I say "amen". (It's not a passive thing to me--I want it to mean something and not be taken for granted). Here is a prayer to which I have no reservations saying amen--meaning, this is my prayer also:
"My prayer is that the Lord will give me discernment; that He will bless me to be honest, frank, and courageous when those are required, and to be discreet, understanding, and sensitive when those qualities are appropriate." --Leonard Arrington, p. 94 of "Adventures of a Church Historian"
"The fundamental principles of our religion are the testimony of the Apostles and Prophets, concerning Jesus Christ, that He died, was buried, and rose again the third day, and ascended into heaven; and all other things which pertain to our religion are only appendages to it."