Peter has addressed his readers concerning living holy lives before God and respectful lives among man. But, all our efforts to be good, righteous, kind, and respectful people will not prevent
“the fiery ordeal that has come on you to test you.”

Many Christians think they can avoid persecution and conflict in this age, in fact, some groups
of believers act as though a “fiery ordeal” is a sign of immaturity or the lack of Christian character.  Since even Christ himself was crucified, Peter says that we “participate in the sufferings of Christ.”
It was the religious crowd, not the world, which came against Jesus. First Peter 3:14 says, “even
if you should suffer for what is right, you are blessed. ‘Do not fear their threats; do not be
frightened.’ ” But, even with this knowledge we need to be reminded “do not be surprised at
the fiery ordeal that has come on you to test you as though something strange were
happening to you.”

Demonstrating the character of Christ and a Christ-like attitude will cause you to “participate
in the sufferings of Christ!” In the face of this ordeal and rejection Peter tells us to “rejoice,”
because we will be overjoyed when his glory is revealed.”

Tertullian, a Christian lawyer, began to write around 196 AD in his preferred language of the Roman legal system, Latin, instead of the preferred language of Greek philosophers, which was Greek. With this language he cut through the obstacles in the Greek language such as the divinity of Christ and the doctrine of the Trinity. With two words from the Roman courts Tertullian used the Latin substantia which we translate as "substance" to say God is one substance, but three persons. The word legal term substantia did not refer to "material" but to "property rights." Thus, the "territory" or "turf" or the "essence" of God is possessed by three "persons." Likewise the word "persons" also is a Roman legal term from the Latin persona which referred to a party in a legal action. Thus, legally in the Latin, a legal party of three could all possess the same territory. Tertullian also rejected the class of Christians called bishops and priest that had arisen to a professional class to administer the church. He believed in the priesthood of each believer, which was a doctrine that would be ignored for 1,300 years.

(Tertullian's writings online here)