1 Thessalonians 3:3

That no man should be moved by these afflictions
Which the apostle endured for the sake of preaching the Gospel among them, and which he feared might be a means of troubling their minds, of shaking their faith, and moving them from the hope of the Gospel; for though none of these things moved him, who was an old soldier of Christ, and used to hardness, and an apostle of Christ; yet these were young converts, and not used to such things, and therefore might be staggered at them, and be offended, as stony ground hearers are; and though the apostle hoped better things of them, yet was he concerned for them, that no one among them might be unhinged by them, or succumb under them:

for yourselves know that we are appointed thereunto;
by the immutable decree of God: afflictions, as to their nature, measure, and duration, are appointed for the people of God, and they are appointed for them; this is the case of all who will live godly in Christ Jesus, and especially of Gospel ministers; of which these saints had been apprized by the apostle, and therefore was nothing new, unheard of, and unexpected, or to be looked upon as a strange thing; and seeing this was the appointment of heaven, and the will of God, they should be patiently endured, and quietly submitted to.