These two sections are confusing and the latter has caused a lot of people some grief. What does it mean for people to force their way in? The parallel to this is in Matthew 11:12, here is a good explanation of the colloquialism of the time and it's meaning as they would understand it. It would be as if an army was sieging a fortified city and one wall breached, the forces would rush in through that breach. Up until this time the only way to salvation was through the Law, with it's sacrifices was actually a foreshadow of Christ. But now the wall, or veil as it were is torn down and those wanting salvation may rush in like the invading army.
Jesus speaks on divorce here, some commentaries think this was a part of the sermon on the mount. Nonetheless one must understand the times and practices to fully understand the instruction. The divorce of that day was quite different than today. There was no court or judge, if a man was unhappy with his wife for any reason he could write her a letter and throw her out. And apparently this happened a lot. It still happens today in a slightly different way, marriages are dissolved for frivolous matters. But what about an abusive spouse? Scripture specifically states adultery is grounds but I also believe physical as well as mental abuse would be grounds. Part of the issue today with divorce is a failed understanding of the marriage commitment before getting married. It's not God's plan for anyone to marry and divorce but it's also not a perpetual sin to be divorced. It may have been something that happened, like any other sin. One can't undo anything but there is grace and forgiveness for all at the cross.