Getting tired
It is not fatigue which tires. The lack of trust that comes with fatigue is exhausting. Not believing in one's dreams and desires is debilitating. Fatiguing without love takes energy away. Fatiguing only to get something back weakens. Fatiguing only for self-interest exhausts. Fatiguing once motivation has been lost tires. Fatiguing without gratitude drains. Fatiguing without joy destroys. In other words: fatiguing without faith debilitates, destroys, and exhausts.
Jesus invites all the men and women of this generation to pray always, to pray always without ever getting tired, because ceasing to pray means ceasing to be connected to God's vibrations and the frequencies of His love. Jesus does not tell this parable in order to inspire us to be insistent, perseverant, obsessive, nagging, suffocating in prayer in order to obtain graces and favors from a fickle and unhearing god; instead He inspires us to pray always without ever getting tired: which is different, very different. Jesus teaches to always pray in order to always stay in touch with God, just as a human being always breathes to stay in touch with air and with life. Human beings must not breath with insistence, perseverance, in an obsessive, nagging or suffocating way; rather they must simply always breathe and never get tired. Jesus inspires humanity to always pray without ever getting tired, and, in order to never get tired of praying, one must never, never, never think badly of God and of His love. This is what Jesus means when he says: But when the Son of Man comes, will he find faith on earth? Faith is only and uniquely possible if one never utilizes his/her intellectual abilities to doubt or to think badly of God and only if one stays perfectly and constantly in touch with Him.