What is devotion?: Devotion is the firm faith in GOD and complete dedication towards his will. Devotion comes from God-knowledge which can be bestowed upon a seeker only by a knower of God. A student who considers himself better knowledgeable than his teacher can't learn the knowledge from the teacher. Likewise God knowledge could be attained only after we give up our ego. The first step of devotion is to surrender ourselves to the the will of God.
Why do we need Devotion (Bhakti) in our life?: We need to ask our selves only. If we care and seek the answer, then it will be blessed to us. However, if we are not concerned and are not willing to sacrifice our comforts and satisfactions, then it may not come to us. No matter how much we are told, ordered and/or listen to the words of divinity, until our heart, mind and soul seek the truth, we will continue to be lost in this material world.
A life that is God-realised and connected with this God, at all times, is a life that of a true devotee. That life has nothing more important and sees nothing beyond the connection which has been established with God. The questions and obstacles of our mind are then no more and no longer exist within us. Our mind knows and shows only the 'One' and is connected only with this God (Nirankar). When we begin to feel the energy that has been bestowed upon us, there is no one else and nothing else that can interrupt the peace of mind and oneness with this omnipresent.
It is not necessary that there is an answer to each of our questions. There are things which we must leave in the hands of the GOD almighty. We may not be strong enough to handle anything that comes our way and we must teach ourselves to accept that.
The enlightened ones, who have been bestowed with the divine knowledge, and those have been connected with the one source; GOD, don't waste their time indulged in materialistic endeavors. They take their decisions responsibly, they are sensible to the words they speak and the actions they commit. Let's pray to this omniscient God to give us sensibility and strength to follow the righteous way of life he has taught us so we could become better human beings. May God bless us all.