Concentration - prepare to meditate
When we want to learn to concentrate, we must be prepared to meditate first. Secondly, we must be prepared to have the faith and the courage to see what is shown to us – not to be disturbed by it, not to be attracted by the beauty that we see, not to be repelled by the ugliness that we may see. So concentration means the instant ability to draw the essence of anything upon which you apply your mind.
Taken from the book "The Principles of Sahaj Marg, Vol. 12", Chapter "Meditation and Education", pg. 214, by Revered Chariji