“Therefore we must pay much closer attention to what we have heard, lest we drift away from it.” Hebrews 2:1 ESV http://bible.com/59/heb.2.1.esv
The following is a helpful taxonomy that gives a means at self examination. It comes from Prayer by Tom Keller. If you choose to be a disciple of Jesus, you will find no more helpful book.
Sailing
Are you “sailing”? Sailing means you are living the Christian life with the wind at your back. God is real to your heart. You often feel his love. You see prayers being answered. When studying the Bible, you regularly see remarkable things and you sense him speaking to you. You sense people around you being influenced by the Spirit through you.
Rowing
Are you “rowing”? Rowing means you are finding prayer and Bible reading to be more a duty than a delight. God often (though not always) seems distant, and the sense of his presence is fairly rare. You don’t see many of your prayers being answered. You may be struggling with doubts about God and yourself. Yet despite all this, you refuse self-pity or the self-righteous pride that assumes you know better than God how your life should go. You continue to read the Bible and pray regularly, you attend worship and reach out and serve people despite the inner spiritual dryness.
Drifting
Are you “drifting”? Drifting means that you are experiencing all the conditions of rowing—spiritual dryness and difficulties in life. But in response, instead of rowing, you are letting yourself drift. You don’t feel like approaching and obeying God, so you don’t pray or read. You give in to the self-centeredness that naturally comes when you feel sorry for yourself, and you drift into self-indulgent behaviors to comfort yourself, whether it be escape eating and sleeping, sexual practices, or whatever else.
Sinking
Are you “sinking”? Eventually your boat, your soul, will drift away from the shipping lanes, as it were—and truly lose any forward motion in the Christian life. The numbness of heart can become hardness because you give in to thoughts of self-pity and resentment. If some major difficulty or trouble were to come into your life, it would be possible to abandon your faith and identity as a Christian altogether.
Choose to Row
In any case—pray no matter what. Praying is rowing, and sometimes it is like rowing in the dark—you won’t feel that you are making any progress at all. Yet you are, and when the winds rise again, and they surely will, you will sail again before them.
From the last chapter of Prayer by Tim Keller