In 1974, aged 20, Mahaney met
Larry Tomczak, with whom he led and taught a large local prayer group named Take And Give (TAG), started by Lydia Little. He says his only reading in theology at that time consisted of the Bible and
The Late, Great Planet Earth by
Hal Lindsey. In 2006,
Ligon Duncan,
Mark Dever,
Albert Mohler, and Mahaney founded the biennial
Together for the Gospel conference, with their continuing participation in It was announced that he was pulling out of the 2014 T4G due to ongoing lawsuits against Sovereign Grace Ministries. He returned in 2016 but withdrew again in 2018. As of 2015, Mahaney was the senior pastor of Sovereign Grace Church of Louisville, a church he planted in the fall of 2012 with Bob Kauflin, Brian Chesemore, Jeff Purswell, and Gary Ricucci. He resigned from the presidency of Sovereign Grace Ministries in April 2013 while planting the church. His leave occurred in the wake of accusations from a former top Sovereign Grace pastor who distributed hundreds of e-mails and internal church documents that portrayed Mahaney as focusing on the sins of others below him in the church hierarchy. After Mahaney's departure, the Sovereign Grace board gave a strong vote of confidence to him, saying that he is "a qualified minister of the gospel and this board approves his pastoral and teaching ministry." After an extensive outside review by Ambassadors of Reconciliation of the charges brought against him and affirmation of the Sovereign Grace board, Mahaney continued to serve as president of Sovereign Grace Ministries. Covenant Life Church, the church Mahaney co-founded and pastored for 27 years left Sovereign Grace Ministries. ==Dismissed sexual abuse lawsuit==