I think it is perhaps true however that we have lost the notion that there is need for perseverance. But we persevere in our faith as we engage in the practices of the Christian life.
The Christian is not saved by faith alone (Jas 2:14-26), but by grace alone (Eph 2:8-9) through a faith that is not mere belief, but through a faith that is completed by obedience (Rom 1:5, 16:26) and love (Gal 5:6), that is, by keeping the commandments of the Lord (Jn 15:6-10; Gal 5:17-21) and working out salvation in acts of charity and goodwill (Mt 25:31-46; Phil 2:12-13). Indeed, faith is never without works.I am reminded of Bonhoeffer who wrote, "To believe is to obey, and to obey is to believe."
Read his article. It is quite good.