Lord said in Bhagvadgita that He will appear as the savior of religion and He descended only in India. In this context once I asked Jananivas prabhu in Mayapur why He appeared only in India is this because degradation of dharma only happened here? He replied Lord is the reservoir of supreme holiness so when He descends with all His parapharnalia He selects most sacred place for His activities i.e. bharatbarsha(India). Thats why Chaitanya mahaprabhu said, " bharat bhumite hoilo janma jahar, janma sarthak kori koro paropakar" one who takes birth in this holy place India he should act as philanthrophst which is nttbonly giving food or shelter but to elevate one from the cluthches of material entanglement , Krsna bhakti.Whereas outside India the religion has suffered most but Lord personally never appeared there but He sent His associates to deliver them. They are the messenger of God. It is said that one vaisnava could deliver a whole universe. Thats why Lord said the He is pleased when someone worships His own devotees.