1 Thessalonians 1:2-10 / Matthew 13:31-35
In his spiritual autobiography Nearer my God, William F. Buckley, Jr., noted that most historically Protestant preparatory schools in New England now tend to treat the word Christianity the way the Victorians treated the word syphilis, although, he noted, Victorians seemed more likely to catch syphilis than modern students at said prep schools were likely to catch Christianity. Many Christians take offense at the more secularized elements of our society treating the Christian faith as though it were some sort of infection which any reasonable society would make the effort to quarantine and isolate, if not eliminate, so as to protect the general public. "The Christian faith," they want to say, "is not an infectious disease. You don't just 'catch' it."
However, to the extent that Christians do live in accord with the new life in Christ given to them in baptism, and by the power of the Spirit, the faith should be infectious. This is, after all, precisely what St Paul commended of the people of Thessalonica. On Paul's view, the Thessalonians had come to embrace the Gospel by having come to know what manner of men Paul and his companions had been among them for their sakes. Moreover, the people of Macedonia and Achaia, and indeed in every place, had come to believe in the Gospel, not so much by Paul's preaching, but by the infectious influence of the Thessalonians' pattern of life, even as the Thessalonians had caught the Gospel, so to speak, from the infectious influence of Paul's pattern of living.
We should, of course, not find this at all surprising. Our Lord himself had assured us that the kingdom of heaven, even from the smallest beginning, is capable of transforming, by even the most minimal contact, all with which it is associated. The kingdom of heaven is like to leaven, which a woman took and hid in three measures of meal, until the whole was leavened. Until the whole was leavened. Note that Jesus did not insist that there should be a sufficiently large proportion of leaven to transform the whole. On the other hand, he did not assert that a small remnant, remaining ever small and without influence on the whole, was all that he desired. Rather, the smallest bit of leaven, while remaining active and true to itself, is sufficient to transform everything else, so that all might be leavened.
In short, the Christian faith is supposed to be contagious, and to the extent that the forces of secularism fear that contact with us might lead to the spread of the faith, their fear is altogether justified. The faith, rightly and unapologetically lived, is likely to make those who encounter it come to believe. To the extent that our neighbors continue to disbelieve, we might well want to ask ourselves why they have not 'caught' the faith. We might choose to lay the blame at their feet, and perhaps we would be right. Then again, we might wonder whether or to what extent we have become followers of the Lord, receiving his word with joy of the Holy Ghost. Might the lingering, if not growing, presence of unbelief be less a cause to shake our fist at a hostile world than to reassess our own public commitment to the pattern of life we have received in Jesus Christ?