I think is easy to see the emotions and responses a Christian or believer would have after reading the poem, but I'm having a hard time to seing it if they are non-Chrisitans or non- believer. Any ideas or suggestions.
The poem is certainly overtly Christian. In the poem, the Rood (Cross) tells the man to share his story (as it is analogous to Christ’s story). So, as it was likely a tale intended to be told to other Christians to support or redeem their faith. To spread Christianity about the world, the author/narrator (the Rood) may have also intended it to be told to so called ‘non-believers’ and non-Christians to convert them to Christianity.
As far as looking at the poem on a secular level, the basic premise is about achieving glory through suffering and that theme is not limited to Christianity.
You could also interpret this as a general redemption story. The Rood, once used to support criminals, ended up being used to support Christ; so, to stretch the analogy, this could be seen as someone (the Rood and analogously, a person) transcending from a life surrounded by criminals to a life surrounded by angels. Christ is resurrected and the Rood is resurrected by, literally, by St. Helen in the 4th century. The poem is specifically Christian but the idea of achieving greatness, peace or wisdom through suffering, toil or work is universal.
Check out "Reader-response Theory." It's the second link below. This is the theory that advocates the validity of a reader's response to a text because there is no one objective interpretation. So, reader-response would advocate a secular reading of a poem that is traditionally read as religious; Reader-response would advocate a religious reading as well. That's the thing; it depends on the reader.