The biblical illiteracy in America is astonishing.
Nowhere in the Christian scriptures, dogmas, teachings or the example of Jesus do we find a directive to make non-Christians obey the peculiar religious instructions of a Christian denomination. (And by “peculiar” I am echoing the words from the book of 1 Peter, of course.)
No one can speak for all Christians in saying that “Christians believe that a certain behavior is required of all people, Christian or not.” These demands are made as if a spokesperson represents all Christians, or all members of a denomination, or even all members of a certain church, but it is a completely false statement. The best that can be said is “I think this is a requirement for behavior acceptable to my God and my belief in my God.”
The thing we are told that marks us as Christians is our behavior. Anyone can say they’re Christian.
The mark of being a Christian is what we do as Christians. Are we kind? Are we merciful? Are we restorative? Are we a blessing? Are we servants? Are we healers? Are we bringing about the kingdom of God (which is the rule of Christ in our hearts) by our actions?
A political kingdom of God is simply not warranted in Scripture, and forcing others to do what we want is not enjoined in Scripture.
We should be very careful when we demand that others obey what we think are requirements for Christians. At some point, others who have strong beliefs that don’t match ours (including Christians with different interpretations of what is “pleasing to God) might take that very power and apply it against us.
And then where will our arguments be? We said we wanted this kind of enforcement of doctrine, and when it is applied to us, we will have no leg to stand on in any objection.
And yeah, this does apply to Palm Sunday, in which Christians celebrate the arrival of Jesus of Nazareth to Jerusalem, a king of those who choose him as king.