{Although we could have insisted on our own importance} as apostles of Christ, yet we became infants in your midst, like a nursing mother cherishes her own children.

just as you know how [we treated] each one of you, like a father his own children,

Whenever they say "Peace and security," then sudden destruction will overtake them like the birth pains of {a pregnant woman}, and they will not possibly escape.

But you, brothers, are not in the darkness, so that the day should catch you like a thief,

So then, we must not sleep like the rest, but must be on the alert and be self-controlled.