Nevertheless, besides the doctrinal differences needing to be resolved, Christians cannot underestimate the burden of long-standing misgivings inherited from the past, and of mutual misunderstandings and prejudices. Complacency, indifference and insufficient knowledge of one another often make this situation worse. Consequently, the commitment to ecumenism must be based upon the conversion of hearts and upon prayer, which will also lead to the necessary purification of past memories. With the grace of the Holy Spirit, the Lord's disciples, inspired by love, by the power of the truth and by a sincere desire for mutual forgiveness and reconciliation, are called to re-examine together their painful past and the hurt which that past regrettably continues to provoke even today. All together, they are invited by the ever fresh power of the Gospel to acknowledge with sincere and total objectivity the mistakes made and the contingent factors at work at the origins of their deplorable divisions. What is needed is a calm, clear-sighted and truthful vision of things, a vision enlivened by divine mercy and capable of freeing people's minds and of inspiring in everyone a renewed willingness, precisely with a view to proclaiming the Gospel to the men and women of every people and nation. (Papal Encyclical, Ut Unum Sint, 25 May 1995).