"Would that the hearts of men could be cleansed from these manmade limitations and obscure thoughts imposed upon them!"  ~Baha'u'llah (from The Book of Certitude)

    Most of the limitations we believe we have are manmade.  Some come from those around us, some come from the general beliefs of all people, and some come from ourselves.  Now we may not be able to change the beliefs and limitations of others, at least not alone, but we can certainly do something about our own.  
    One belief we can do something about is aging.  Have you ever visited a hospital for the mentally challenged?  If so, you may have noticed a number of residents who look much younger than their chronological age.  Why is that?  I'm sure the doctors and medical researchers have explanations based on chemistry, but I believe a big part of it is that these people simply don't understand the rules of aging and what they should look like at age thirty, or forty, so they don't do it.  Another example is the well known one of Dr. Bannister who became famous for being the first runner to break the three-minute mile.  He did it partly because he was a great runner, but also because he didn't know about the supposed limit so he wasn't limited by it.  After he broke the supposed four minute barrier, other professional runners now knew it was possible, and quickly beat Bannister's record.  
    We all set limitations on ourselves and some of them can affect our spiritual development.  Consciously, or subconsciously, we believe we are not worthy.  Or we think it is something only a saintly person can achieve.  Or we think that we can't be reasonably successful in the material world and develop spiritually as well.  None of those beliefs are true, yet believing them will limit our growth.  Simply telling ourselves regularly that those things are not true can help.  Hear are a few affirmations you can use, or make up your own for your specific situation:

• I am filled with the creative power of God
• God has no limitations, so I, as a child of God, have no limitations
• I am worthy of being a part of God's divine plan