I have recently begun re-reading J.I. Packer's
Knowing God. It is for good reason considered a classic--and if you read one book this year, outside of the Bible, this should be it. Here he is on one of the themes of my ongoing discipleship--what following Christ looks like from an emotional (or affective) viewpoint. (I, for one, struggle mightily with my emotions, and long for them to be part of God's regenerative work in my life.) Here is Packer:
The emotional side of knowing God is often played down these days, for fear of encouraging a maudlin self-absorption. It is true that there is nothing more irreligious than self-absorbed religion, and that it is constantly needful to stress that God does not exist for our 'comfort,' or 'happiness,' or 'satisfaction,' or to provide us with 'religious experiences,' as if these were the most interesting and important things in life. It is also necessary to stress that anyone who, on the basis of 'religious experiences,' 'saith, I know him, and keepeth not his commandments, is a liar, and the truth is not in him' (1 John 2:4; cf. verses 9, 11, 3:6, 11, 4:20). But for all this, we must not lose sight of the fact that knowing God is an emotional relationship, as well as an intellectual and volitional one, and could not indeed be a deep relation between persons were it not so. The believer is, and must be, emotionally involved in the victories and vicissitudes of God's cause in the world, just as sir Winston [Churchill's] personal staff were emotionally involved in the ups and downs of the war [WW II, that is]. The believer rejoices when God is honored and vindicated, and feels acute distress when he sees God flouted. Barnabas, when he came to Antioch, 'and had seen the grace of God, was glad' (Acts 11:23); by contrast, the psalmist wrote, 'rivers of water run down my eyes, because they keep not thy law' (Psalm 119:136). Equally, the Christian feels shame and grief when convicted of having failed his Lord (see, for instance, Psalm 51, and Luke 22:61f.), and from time to time knows transports of delight as God brings home to him in one way or another the glory of the everlasting love with which he has been loved ('transported with a joy too great for words' [1 Pet. 1:8, NEB]). This is the emotional and experiential side of friendship with God. Ignorance of it argues that, however true a man's thoughts of God may be, he does not yet know the God of whom he is thinking."