Even though we sometimes plan to practice the Dharma, we usually plan to do so tomorrow or the day after. However, we can't tell when we're going to die. If we were guaranteed a hundred years to live, we'd be able to plan our practice long-range, but we have not the slightest certainty of when we're going to die. Therefore, it's very foolish to put our practice off. Some people die in the womb before they're even born; others die as small babies before they've even learned to walk. There's no logic in thinking that we're going to live long.
Tsenzhab Serkong Rinpoche
Outside enemies are like reflections in a mirror, reflections of our own image reflected back at us. Just as there is no one in the mirror apart from the reflected image of our own body, all of these outside problems, obstacles, enemies, and so on are the reflections of our own defilements. Therefore, if we control our inner defilements, all of our outer enemies and obstacles naturally disappear.
His Holiness Sakya Trizin
Getting butter from milk is only possible because milk already contains cream. No one ever made butter by churning water. The prospector looks for gold in rocks and not in wood chips.
Likewise, the quest for perfect enlightenment only makes sense because buddha-nature is already present in every being. Without that nature, all efforts would be futile.
Jamgon Kongtrul Lodro Thaye
As for some further explanation of the term "bodhisattva", its definition is very specific. Sometimes "bodhisattva" is misunderstood as simply meaning somebody who has concern for other sentient beings, and who cares for them. Although this is very good, and constitutes one of a bodhisattva's ways of dealing with others, it does not make a person a bodhisattva.
The defining characteristic of a bodhisattva is the development of bodhicitta - the wish to attain enlightenment in order to benefit all beings. Once this wish has arisen one becomes a bodhisattva.
When we like to give people food, clothing, and shelter, this is very good, and a bodhisattva should do these things if he or she can do so - but through such actions alone we will not become bodhisattvas.
A bodhisattva is someone who is totally inspired by the aspiration to realize enlightenment for the benefit of all beings. This is bodhicitta, the characteristic of a bodhisattva.
The Tibetan expression for bodhicitta is 'jang chub kyi sem'. Here, 'jang chub' means "enlightenment", and 'sem' means "mind"; 'kyi' is a particle indicating that "enlightenment" describes a type of "mind". Thus the phrase means "mind of enlightenment", or "mind focused on enlightenment".
The word for bodhisattva, 'jang chub sem pa', means one who has this 'jang chub kyi sem'. The word for buddhahood also uses these terms: it is called 'jang chub kyi go pang', or "the state of enlightenment". So all these are interrelated; in this way the term "bodhisattva" is totally connected with enlightenment.
Tai Situ Rinpoche