When I look at Christ, I see someone whose devotional life had real bearing on their life. Jesus is certainly a special case, but his 40 days of fasting were sustained by feeding on the Word of God. This is evidenced by his strategy for fending off Satan and his teaching in the synagogues directly after (Luke 4). From his times of prayer outpoured clarity on the apostles to call, power to heal, and commands and parables about the Kingdom life (Luke 6).
Every so often I think we need to ask ourselves if our devotional activities are bearing any fruit. Francis de Sales describes three stages of spiritual growth: a beginning awareness--grace; strength to do good works--charity; and the ability to do good frequently and promptly--devotion. He also says that a devoted life should grow our love for God and our love for others. I have strength to do good works, but there is still often an initial apprehension to do them frequently, devotion as he calls it. I think I'm afraid to loose control, especially of my time. Organizing my time gives a sense of security and stability. I would feel lost without that. One barometer then for me and the devotional life is the looseness with which I spend my time on others. How would you measure the effectiveness of your devotional life?