The use of affirmations goes along with prayer and meditation. Affirmations can be employed to emphasize our relationship with the divine or our own inner healing powers. People suffering from negative thoughts about themselves, are often trapped in self-doubt. Affirmations can be very strengthening in such conditions.
Yet affirmations should lead to action and not substitute for it. To do anything in life requires a belief that one can do it and a positive intention to make the effort. In such cases one cannot use the affirmation as an excuse for inaction.
Visualization goes along with prayer and meditation. One may visualize healed and improved conditions that one wishes to achieve. One can also direct healing energy to those who are sicker or to the parts of ones own body that need improvement. Such visualizations usually employ certain colors and mantras to be directed along with the breath. Visualizations can also be of deities or beautiful natural scenes to clear the mental field.