Śrī Caitanya Mahāprabhu is preaching prema, means love of Godhead. That is the only necessity to understand in human form of life. Premā pumartho mahān.
There are other necessities for those who are not devotees. Those necessities are dharma artha kāma mokṣa (SB 4.8.41, Cc. Ādi 1.90). Generally, in the material world everyone has necessity of gratifying his senses. So sometimes, under the cover of religiosity, they want to satisfy senses. The same thing... Just like one goes to church or temple to mitigate some material necessities. Just like the Christians go to the church for meeting the problems of bread; similarly, the Hindus or the Muslim, everyone goes to church, temple or mosque to pray something material: "God, I am very distressed. Kindly get me relief from this distressed condition." Or "God, I am in need of money, I am very poor. Kindly give me some money." Or any other, "I am now implicated in war." Just like Churchill, he introduced that everyone should go and pray for victory. So England was also praying for victory, and Germany was also praying for victory. So (chuckles) God is perplexed. (laughter) The thief is praying to God that "This night, I may steal without any hindrances." And the householder is praying, "My Lord, thief may not come here and steal my goods." And God has to adjust everything. So just imagine how much busy is God. There are millions and trillions of living entities. Each one of them, if they are at all interested in God—not all—so they are praying. Everyone is praying, "God, give me this benediction. Give me this benediction." So this is not pure devotional service. For some material profit, one should not become a religious person or devotee of God. Of course, it is better than the person who is not at all interested in God. That is stated in the Bhagavad-gītā, catur-vidhā bhajante māṁ sukṛtinaḥ arjuna. Unless one is pious, he cannot approach God.
So one should be pious and without any motive, not only pious. Pious is the first condition, who can approach God; otherwise he does not.