I am curious why, if you are an ordained minister, tracts/pamphlets/flyers/handouts of a similar religious nature might be offensive? Is it because they are from a competing sect? Perhaps they are JW or Mormon? I suspect that my denomination (a Calvary Chapel Fellowship) may differ from yours, yet I would never consider tossing flyers from yours or anyone else's faith into the trash. Instead of suffering angst on our differences, let us instead concentrate on what we have in common - Christ.
If we expect people to respect OUR faith, or our particular subset of the faith, then we must first learn to respect those of others. Ultimately, the employer will decide what is or is not appropriate to be placed in the workplace - as you have discovered.
The employer did nothing wrong, and you have now learned that this is permitted. Time to move on from it.