Buddha was speaking about reality. Reality may be one, in its deepest essence, but Buddha also stated that all propositions about reality are only contingent. Reality is devoid of any intrinsic identity that can be captured by any one single proposition - that is what Buddha meant by "voidness." Therefore, Buddhism strongly discourages blind faith and fanaticism.

If the mind is tranquil and occupied with positive thoughts, the body will not easily fall prey to disease

Calm mind brings inner strength and self-confidence, so that's very important for good health.

When, from the depths of your heart, you spontaneously wish all beings to find true, lasting happiness, this is great love.

Spiritually, yes, now many people knows Tibetans in spiritual field are very, very advanced but in material field is very, very backward.

...there is an intense delight in abandoning faulty states of mind and in cultivating helpful ones in meditation.

External circumstances can contribute to one's happiness and well-being, but ultimately happiness and suffering depend on the mind.