If you haven't filled up your reading card for 2015, may I suggest The Letters of Samuel Rutherford? You will rarely find a pen pal so encouraging and spiritual. Even reading one or two of his letters a day is a great way to be reminded of what true, Christ-centered spirituality really looks like. C.H. Spurgeon himself said that Rutherford's letters were the closest thing to inspiration that can be found in the writings of men!
Though he's best known for his political treatise _Lex Rex, _it is Rutherford's _Letters _that have carried many souls back to Scripture and Scripture's Christ for help in dark times. Many of his letters were written from his own prison cell, where he had deeper communion with Christ than we often think possible.
Consider these encouraging quotes I found just flipping through the book this morning:
I cannot but write you, that this which I now suffer for is Christ's truth; because he hath been pleased to seal my sufferings with joy unspeakable and glorious. (To Robert Douglas)
...the mourning for the husband of your youth be by God's own mouth the heaviest worldly sorrow; and though this be the weightiest burden that ever lay upon your back, yet ye know (when the fields are emptied and your husband now asleep with the Lord,) if you shall wait upon him who hides his face for a while; that it lies upon God's honor and truth to fill the field and to be a husband to the widow...The Lord has pierced the vessel, it will be known whether there be in it wine or water. Let your faith and patience be seen that it may be known, your only beloved first and last has been Christ. (To Lady Kenmure on her husband's death)
Brother, I am comforted in my royal Prince and King. The world knows not our life, it is a mystery to them. We have the sunny side of the world, and our paradise is far above theirs; yea, our weeping is above their laughing, which is but like the cracking of thorns under a pot...I find my prison the sweetest place that ever I was in. My Lord Jesus is kind to me, and has taken the mask off his face... (To James Murray, from prison)
Take and read! You won't regret it.