'and since when was enduring persecution and hostility part of being a Christian?'
Forever! Jesus Himself warned us that His followers would go through persecution. All the Apostles and early Christians were persecuted and very many killed. There are warnings throughout the NT of the suffering Christians would go through, which in the end times would get worse and worse.
Whether we are approaching those times no-one can know, but the exponential increase in the persecution of Christians makes one wonder.
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