To most people, when you talk about being strong, they think of someone with big muscles who can lift a lot of weight or pull something very large and heavy, but that isn't the only kind of strength.  There is also mental and spiritual strength.  It's important when you are planning to develop your spiritual side, to develop mental and spiritual strength.  That is because, in the very materialistic world we live in today, the idea of mental and spiritual discipline is not valued by many.  If you don't develop this mental and spiritual discipline, you are easily swayed by friends and relatives who are not interested in spiritual development and try to convince you to do things with them that you know you shouldn't do when you are trying to grow spiritually.
    If you were fortunate enough to have parents who set rules for you when you were young helping you to develop self-discipline at a young age, than you are already well on your way.  If you were not so lucky, than you have to develop that self-discipline, that spiritual and mental strength now.  The way to do it is to start small.  Don't try to completely change overnight.