Christians in the first century were as human as those in the twentieth. The Gentile churches fared little better. We probably would have been in absolute despair over the squabble at Philippi, but Paul wrote an epistle of joy.
Spiritual cultivation takes time.
Then there was Corinth. Problems in this church were so numerous and so diverse that Paul's corrective letter to the Corinthians has commonly been regarded as a kind of catalog of church sins and their remedies. The Smyrneans and Philadelphians received Christ's highest commendation, but probably not that of their fellow Christians in the rest of Asia. Neither of the two boasted physical strength and the Smyrneans were in deep poverty. The Lord also encouraged the faithful in each of the other five to be steadfast.