A) Work out of the day (week?) - None. ;)
I've begun to realize that an enormous part of saving faith is that I have the assurance that I will still have faith tomorrow. It's a bit of a weird concept the more I think about it - I won't lie.
There are those days when the only thought that prevails on your mind is "I can't do this. I absolutely can not do this anymore. This is awful." Insert some stronger language if you'd like (most of my days like that I do, but usually only in my head :-p) and then repeat it over and over throughout the day. This thought has bludgeoned me at work, it's bludgeoned me in dating relationships, it's bludgeoned me in roommate situations, it's bludgeoned me in friendships, and it's bludgeoned me about my Dallas Cowboy fan-ship (but we won't get into that.)
I'm not sure if it has a set schedule, or if something triggers it, but some days I just do not have what it takes to accept my current position in life and all I have to say to God, myself, or anyone who will listen is "I can't do this any more, I have to find something else."
So - there we have it, the set up. Sometimes we have days where we all we can do is say "I can't do this one more day." Now, why?
One caveat I'll make here is that a while ago I was expressing such a situation to my father and he said "You know, some days will be like that, some times it is just a dry season and you just have to ask yourself - 'did anything change between yesterday (or whatever time you were ok) and today? Is this a real disgruntlement or just a temporary shift in my feelings'" - That's one of the best pieces of advice I have received on the issue, bar none. Monday, I'm fine at work. Tuesday I do the same thing I did Monday but my loathing for it has increased exponentially - nothing has changed other than that Tuesday I've decided things are hopeless. Come Wednesday, I all too often find that I am just fine again. So - point 1 - ask yourself what changed. If the answer is nothing... it's one of those days :-p
Secondarily, and back to the main point. I think this issue stems from the limitations and rules we put on our faith and God's grace. We feel like our reservoir of strength won't last one more day. Again - here's the twist... It won't. We try to mentally combat tomorrow's troubles with today's strength, even though that matches nothing about the way God moves through his Word or his people.
Deuteronomy 33 - "As your days are, so shall your strength be"
Lamentations 3 - "The lord's lovingkindess never fails, his mercies are new every morning, great is your faithfulness"
The story of the manna in the wilderness is another real fun place to look. Or about half of what Paul says in the new testament.
God's allotment of mercy today will NOT be big enough for tomorrow's troubles - but it will always be enough for today's. Our God is perpetually giving us just what we need and forcing a reliance on him. That's the story of salvation and it's the story of sanctification as well. When we feel like the strength given us for the day won't last til tomorrow... we're right. Just like the manna given to the Israelites in the wilderness - it will feed us today, and when tomorrow comes it will be gone - there was only dependence for them while they were in the desert, no storing up.
How does all this tie back into my original point that the assurance of faith tomorrow is a huge part of faith today? One of God's greatest mercies is that in that portion of mercy he gives us each day is the key to surviving the next. The faith that when tomorrow does come, and all its troubles with it, God's mercies come as well. At the end of the day, when I know that my strength is at an end, my despair only arises because I haven't used the last God-given resource for that day. The full knowledge that tomorrow God's mercy will be there once again, and will once again match my troubles. How tight is that? How often do I forget that? A huge part of saving faith is the assurance that I can once again have faith tomorrow. So when you have one of those days, try to remember that when troubles rise, mercy comes and that God's mercy today will cover my troubles. If you can't do it again on the strength given you today - don't fear... you won't have to.