Efforts to cover up the crimes had caused even greater harm, he said in a letter delivered to US bishops attending a retreat in Chicago.
He urged the bishops to end internal bickering and show unity as they tried to tackle the crisis.
The Pope’s comments on child abuse have grown stronger over time.
In an extensive letter released by the Vatican, the Pope says the “hurt caused” has generated “division and dispersion” within the ranks of US bishops.
“God’s faithful people and the Church’s mission continue to suffer greatly as a result of abuses of power and conscience and sexual abuse, and the poor way that they were handled,” he wrote, adding bishops had “concentrated more on pointing fingers than on seeking paths of reconciliation”.
“Combating the culture of abuse, the loss of credibility, the resulting bewilderment and confusion, and the discrediting of our mission urgently demands of us a renewed and decisive approach to resolving conflicts,” the Pope wrote.
Attempts to restore the institution’s credibility must be based on rebuilding trust, he added.
Next month, US bishops will join their counterparts from across the world for an extraordinary meeting at the Vatican to find ways of tackling the crisis.
A report last year by a grand jury in Pennsylvania identified more than 1,000 victims abused by hundreds of priests over seven decades in that state alone.
In July of last year, the pontiff accepted the resignation of Cardinal Theodore McCarrick, one of the US Church’s most prominent figures, following allegations he had sexually abused a teenager.
In October, Cardinal Donald Wuerl, the archbishop of Washington DC, stepped down over his handling of abuse cases.
Pope Francis called for “decisive action” when he was elected in 2013, but critics say he has not done enough to hold to account bishops who allegedly covered up abuse.
In late December, he urged priests who had offended to surrender to the law, in preparation for “divine justice”.