Catholics become weak when they do not take their faith seriously. When you recite the creed or pray the Our Father, do you really mean every word you say? Above all, how much does the Holy Eucharist mean to you? After you receive this Most Blessed Sacrament at Mass and leave the church afterwards, do you still think about your Lord? As long as Christ remains superficial in your life and you do not commit yourself to love him with all your heart, with all your mind, and with all your soul, you remain weak.