Jesus expected His disciples and the crowd to have faith so as to expel demons (see Mk 9:19). Jesus invited the father of a possessed son to have greater faith (see Mk 9:23). Jesus connects faith with prayer (Mk 9:29).
Will you pray to have a greater faith? (see Lk 17:5) How much will you pray for greater faith? Will you pray a Holy Hour for nine days to obtain greater faith? How much do you want a greater faith?
To grow in faith, will you persevere in studying and reading the teachings of the Church, especially the Bible? "Faith comes through hearing, and hearing by the word of God" (Rm 10:17, our translation).
The more we love Jesus, the more we want to have a deeper faith in Him. Motivated by love, we are willing even to suffer when necessary to grow in faith (see 1 Pt 1:6ff).
Pray for and in faith. Feed your faith. Suffer for greater faith. We are saved by grace through faith (Eph 2:8). "When the Son of Man comes, will He find faith on earth?" (Lk 18:8, RSV-CE)