How do you know when you have crossed the line from simply having confidence in yourself and your abilities to falling into the sin of pride? I sometimes feel that if I have high self-esteem, or am very sure on an issue; then I am being proud.
Gentleness and lowliness in heart are among the first blessings we observe in the Lord Jesus Christ's earthly example. The Lord Jesus Christ tells us, "Learn from Me, for I am gentle and lowly in heart and you will find rest for your souls" (Matthew 11:29).
St. John El-Dargy further explains this in saying, "The Lord said, "learn from Me, for I am gentle and lowly in heart." It is not from an angel, a man, or from a book you learn lowliness of heart, but "from Me." That is how we learn humility, from the meekness shown by the Lord Jesus Christ.
Acquiring humility requires continuous exercises. First we must know our weaknesses. St. Isaac said, "Blessed is the person who knows his weakness, as such knowledge is a good principle and a source of every good thing. Because if he knows his weakness, he avoids slackness and asks for God's help and relies on Him."
True humility is attained by work and the knowledge that outside behavior affects the inside human feelings. The Lord Jesus Christ taught us how to attain humility in a very practical way. As He washed the feet of the holy disciples, he also commanded them to do likewise.
St. Basil the Great said, "Sciences and professions are not learned without practice. Who wishes to learn Philosophy, Literature, or one of the professions, needs to practice working at it in order to perfect it. Likewise, humility and other decent virtues cannot be perfected without practice."
St. Augustine said, "The inside and the outside of man are united one to the other and each one is fond of the other to a great extent. So that when the body becomes humble and lowly, the heart gets an inner feeling of humility. Hence, if you bend down to kiss your brother's feet, the humility in your heart is moved or strengthened if it already existed. External humility in front of brethren, such as serving them and kissing their feet, simple dressing, and menial jobs, all these give birth to humility in the heart, and keeps and strengthens it, if it is already there."
The difference between being proud and self confident lies in how much do you trust yourself and how much you trust God. The self-confident person trusts in God and that is why he is self confident "I can do all things through Christ which strengtheneth me" (Philippians 4:13). The proud person trusts in himself and not in God.