In the New Testament "He has made us to be a kingdom, priests to His God and Father" (Rev 1:6). In the Old Testament the priests "shall be clothed with linen garments; and wool shall not be on them while they are ministering . . . [because] they shall not gird themselves with anything which makes them sweat" (Eze 44:17-18). In Christianity doing anything that produces sweat is considered doing it "in your own strength." One of Christianity's basic tenets is that "by grace you have been saved through faith; and that not of yourselves, it is the gift of God" (Eph 2:8). But even though faith is from God it must be exercised. Jude said he "felt the necessity to write you appealing that you contend earnestly for the faith which was once for all handed down to the saints" (Jude 3). "'From the days of John the Baptist until now the kingdom of heaven suffers violence, and violent men take it by force" (Mt 11:12). It sounds like exercising faith is hard. It is "tested by fire" (1Pe 1:7) and "the testing of your faith produces endurance" (Jas 1:3). "Whatever is born of God overcomes the world; and this is the victory that has overcome the world--our faith" (1Jn 5:4).
On an individual level "the faith which you have, have as your own conviction before God" (Ro 14:22). "God has allotted to each a measure of faith" (12:3). "Test yourselves to see if you are in the faith" (2Co 13:5). But if you doubt yourself then your "eating is not from faith; and whatever is not from faith is sin" (Ro 14:23). Your relationship with God is strengthened when you exercise faith. Nehemiah was the kin's cupbearer. One day the king asked why he was so sad. Nehemiah told him the truth and the king asked how he could help. Then Nehemiah's rapport with God was demonstrated when, on the spot, he "prayed to the God of heaven" (Neh 2:4). God's answer was instantaneous and Nehemiah requested to be sent to Judah to rebuild the city (:5). On a group level God gives various workers "for the work of service, to the building up of the body of Christ; until we all attain to the unity of the faith" (Eph 4:12-13). Paul told them they should be "standing firm in one spirit, with one mind striving together for the faith of the gospel" (Php 1:27). "'He who overcomes, I will grant to him to sit down with Me on My throne, as I also overcame and sat down with My Father on His throne'" (Rev 3:21).