We might think, “It is important to practice Dharma in order to have spiritual experience and inner peace, but I will pursue that path in future lives.”
But the Buddha said that it is not easy to obtain a precious human life with the freedom and endowments that we now have, because we need to have much good karma, causes, conditions, and circumstances to obtain it.
So we must practice in this very lifetime while we do have this precious human life.
Shāntideva said: It is exceedingly difficult to obtain a human life with the freedoms and endowments. When you have got the chance to fulfill the goal of life, If you do not take advantage of it, How can you get this opportunity again?
(Source: Thondup, Tulku. Enlightened Journey: Buddhist Practice as Daily Life. Shambhala. Kindle Edition.)