The essence of charity is for the servant to recount the blessings of his Lord, and to render thanks unto Him at all times and under all conditions.

Bahá’u’lláh, Tablets of Bahá’u’lláh, p. 156

In all the cycles of the prophets the philanthropic affairs were confined to their respective peoples only -- with the exception of small matters, such as charity, which was permissible to extend to others. But in this wonderful dispensation, philanthropic affairs are for all humanity, without any exception, because it is the manifestation of the mercifulness of God. Therefore, every universal matter -- that is, one that belongs to all the world of humanity -- is divine; and every matter that is sectarian and special is not universal in character -- that is, it is limited. Therefore, my hope is that the friends of God, every one of them, may become as the mercy of God to all mankind.

‘Abdu’l-Bahá, Lights of Guidance, p. 302

Regarding your question concerning helping the poor: The Bahá’ís should not go so far as to refrain from extending charity to the needy, if they are able and willing to do so. However, in this, as in many other things, they should exert moderation. The greatest gift that we can give to the poor and the down-trodden is to aid to build up the divine institutions inaugurated in this day by Bahá’u’lláh as these institution, and this World Order when established, will eliminate the causes of poverty and the injustices which afflict the poor. We should, therefore, do both, support our Bahá’í Fund, and also be kind and generous to the needy.

Shoghi Effendi, Lights of Guidance, p. 124-125