From a mental health viewpoint, as opposed to a religious viewpoint, I would say this. One of the most important things in mental health is stress management. Very often, cases of depression are caused by prolonged, high stress. Mindfulness meditation and use of mindfulness in daily life have been shown to be useful in stress management.
"How Meditation Helps You Handle Stress Better" in the January 27, 2017 issue of Time has an interview with Elizabeth Hoge of the Georgetown University Medical Center, chief researcher in the most convincing evidence yet that Mindfulness-Based Stress Reduction (MBSR) is effective stress reduction. The study, published in the journal Psychiatry Research, reports lower hormonal and inflammatory response than people in the control group who didn’t practice mindfulness.
MBSR does not just teach mindfulness. It includes gentle yoga. If you wanted to include a practice to your mindfulness, controlled breathing would be a good choice.
Of all the traditional mind-body practices (meditation, etc.), the one with the best evidence for affecting mood disorders is yoga breathing. Slow breathing is used for treating anxiety, depression, panic disorder, and PTSD. It's safe and it doesn't take any training. You can find out about the work of psychiatrists Richard Brown and Patricia Gerbarg and PTSD therapist Emma Seppala in my recent answers.
Mindfulness apps are very popular. A reviewer says that the best one is Mindful Life Project and it's absolutely free. The most popular app is Headspace, which is the most expensive but it has a 30-day trial you can use over and over. Calm has a free breathing exercise that's really useful.