When Beaker was in the seventh grade, his youth pastor introduced him to his friend Rich Mullins, and the two soon became collaborators. Beaker co-wrote, performed, and toured with Rich Mullins for several years. The first song they wrote together was "Boy Like Me, Man Like You", a 1991 hit for Mullins. Beaker is also responsible for writing the modern praise chorus "Step By Step" ("Oh God, you are my God, and I will ever praise you..."). He was also instrumental in co-founding the Kid Brothers of St. Frank with Rich Mullins, and well as co-writing a musical about Saint Francis of Assisi entitled Canticle of the Plains.
In the mid-90s, Beaker dropped out of the spotlight to focus on family life. He and his wife Julie had a son named Aidan, for whom Rich Mullins penned his hit song "Let Mercy Lead".