I call to mind the words of Russia’s great ascetic and 19th Century theologian, Metropolitan Philaret (Drozdov): “It is better to sit and think about God, than to stand and think about [the pain in] your legs.” Of course, if you become tired and do not have the strength to remain standing, you should sit down. The physical attitude in which you pray is not what is most important. What is [important] is that in your thoughts you be close to God.