The Indian teacher Narada wrote:
“Bhakti is intense love of G-d…When a man gets it, he loves all, hates none…” 
Swami Vivekananda taught on this:
“Bhakti Yoga is is a real, genuine search after the Lord, a search beginning, continuing and ending in Love…The one great advantage of Bhakti is that it is the easiest and fastest way to reach the great divine end in view; its great disadvantage is that in its lower forms it often degenerates into hideous fanaticism. The fanatical crew in Hinduism, or Mohammedanism, or Christianity [or Judaism, etc.] have always been almost exclusively recruited from these worshippers on the lower planes of Bhakti. That singleness of attachment (Nishthâ) to a loved object, without which no genuine love can grow, is very often also the cause of the denunciation of everything else. All the weak and undeveloped minds in every religion or country have only one way of loving their ideal, i.e. by hating every other ideal. Herein is the explanation of why the same man [or woman] who is so lovingly attached to his [or her] own ideal of God, so devoted to his [or her] own ideal of religion, becomes a howling fanatic as soon as he [she] sees or hears anything of another ideal. This kind of love is somewhat like the canine instinct of guarding the master’s property from intrusion…Again, the fanatic loses all power of judgment…The same man [woman] who is kind, good, honest and loving to people of his [her] own opinion, will not hesitate to do the vilest deeds…against persons beyond the pale of his [her] own religious brotherhood.
But this danger exists only in that stage of Bhakti which is called preparatory (Gauni). When Bhakti has become ripe and has passed into that form which is called the supreme (Parâ), no more is there any fear of these hideous manifestations of fanaticism; that soul which is overpowered by this higher form of Bhakti is too near the God of Love [or: G-d's Love for us or ours for G-d] to become an instrument for the diffusion of hatred.” 
Rabbi Morris Lichtenstein similarly taught:
“The child who is taught to love G-d also attains to love of his fellow-man. For he is taught at the same time that G-d, or the Divine Mind, makes His abode in every being of His creation [animate and inanimate] and that he dwells in man as in the rest of creation, and that His presence in man constitutes the noblest aspect of man. It is therefore impossible to love G-d and hate man, for these are inseparable.” 
In Jewish/Hebrew terms, “Bhakti” is “Ahavat Ha-Shem” — loving G-d; especially in the form of “Hasidut” — intense devotional love of G-d.
We sometimes experience this “bhakti” during or after prayer. We might not feel overflowing love, but we also don’t feel deep animosity (or shouldn’t). Such calm can only be temporary, however, as more typical thoughts and feelings invariably re-overwhelm our attention.
The deeper goal of prayer is — or should be — the gradual culturing of the heart to maintain this love even after prayer.
Ernest Holmes gives us a hint on how to begin:
“We [meaning all of us] believe in actually talking to G-d and then letting G-d answer. But perhaps in our confusion we talked at G-d rather than to Him. We have told Him how terrible everything is, how unhappy we are.
Try this: Sit or lie in complete repose and then tell G-d how wonderful He is and how glad you are; how grateful. It is at times like these that we are truly tuning in to the Divine, and the Divine will always respond to us.” 
 Narada; “Bhakti Sutras,” quoted in:
Vivekananda, Swami; Bhakti Yoga; © 2001 by Advaita Ashram; p. 3
[note: This is the 21st impression of this publication; Swami Vivekananda passed in 1902. His words -- so relevant today -- were written well over 100 years ago.]
 Vivekananda, Swami; Bhakti Yoga; p. 3-5
 Lichtenstein, Rabbi Morris; Jewish Science and Health; Jewish Science Publishing Co., © 1925; p. 123
 Holmes, Ernest; Living the Science of Mind; © 1984 by Science of Mind Communications; De Vorss Publishers, p. 272