Bhaktamar is not a combination of Mantras(chants), its strotram (hymns of praise).
When we recite a mantra, Bhakti (devotion) is not a necessary condition. But Strotra is nothing but hymns of praise that involves devotion. In Bhaktamar, Acharya Mantunga praises the greatness of Tirthankar Rishabhdev. It does not mean, that when Mantunga Acharya recited the strotra only bhakti did the job, it’s actually the Beejakshar (बीजाक्षर) used along with extreme devotion, that did the real job.