Just when all seems to be going right, challenges often come in multiple doses applied simultaneously. When those trials are not consequences of your disobedience, they are evidence that the Lord feels you are prepared to grow more (see Prov. 3:11–12). He therefore gives you experiences that stimulate growth, understanding, and compassion which polish you for your everlasting benefit. To get you from where you are to where He wants you to be requires a lot of stretching, and that generally entails discomfort and pain.
To exercise faith is to trust that the Lord knows what He is doing with you and that He can accomplish it for your eternal good even though you cannot understand how He can possibly do it.
I like the talk because it reminds me that things are hard, but that it will all be okay. There is a reason for everything we go through, even if we don't know what it is or how things will turn out.