September 1

In regard to your question: we must not be rigid about praying; there is not a set of rules governing it; the main thing is we must start out with the right concept of God, the Manifestation, the Master, the Guardian -- we can turn, in thought, to any one of them when we pray. For instance you can ask Bahá'u'lláh for something, or, thinking of Him, ask God for it. The same is true of the Master or the Guardian. You can turn in thought to either of them and then ask their intercession, or pray direct to God. As long as you don't confuse their stations, and make them all equal, it does not matter much how you orient your thoughts. 
- Shoghi Effendi  (From a letter dated 24 July 1946 written on behalf of Shoghi Effendi to an individual believer; The Compilation of Compilations, Vol. II, The Importance of Prayer, Meditation and the Devotional Attitude)