sva-pada-mule patitam tam arbhakam
vilokya devah kripaya pariplutah
utthapya tac-chirshny adadhat karambujam
When Lord Nrsimhadeva saw the small boy Prahlada Maharaja prostrated at the soles of His lotus feet, He became most ecstatic in affection toward His devotee. Raising Prahlada, the Lord placed His lotus hand upon the boy's head because His hand is always ready to create fearlessness in all of His devotees.
The necessities of the material world are four -- ahara, nidra, bhaya and maithuna (eating, sleeping, defending and mating). In this material world, everyone is in fearful consciousness (sada samudvigna-dhiyam), and the only means to make everyone fearless is Krishna consciousness. When Lord Nrisimhadeva appeared, all the devotees became fearless. The devotee's hope of becoming fearless is to chant the holy name of Lord Nrisimhadeva. Yato yato yami tato nrisimhah: wherever we go, we must always think of Lord Nrisimhadeva. Thus there will be no fear for the devotee of the Lord.
(Srimad-Bhagavatam 7.9.5, Purport)