One of the very satisfying ministries that I have felt called to in retirement is that of mentoring other clergy. In some cases it has been an official mentoring in connection with a nearby seminary. In other cases, it has been more informal. In all cases it has allowed me to extend my ministry by drawing on the resources of my forty years in ways that are helpful to others. Of course one has to be careful that one does not give the impression that you are the fount of all wisdom that needs to correct the errors and inexperience of the uneducated novice. However, with appropriate sensitivity, you have much to offer those who are still engaged in ministry.
Think about some of the clergy that you know in your community. Pick out one that you have met and invite him or her to lunch. You know from your own experience that ministry is a lonely experience. Often just by asking them how it is going, you will provide an opportunity for them to process their current experiences. Not infrequently, from such conversations, you will hear of particular challenges that can benefit from your own experience. Even if that is not so, there is great value in simply offering a listening ear.
If you offer the opportunity for two or three clergy to share about their ministry and have a conversation with someone who both understands the stress and challenges of ministry and is not active in a current ministry that might be seen as competitive, I think you will find that you can offer a supportive hand.
I will stress that you often have to be the one to take the initiative in these invitations. Even after we have had a valuable conversation and the other clergy has expressed their thanks for the conversation, the demands of their current ministry often results in them not taking the initiative for the next lunch. But when you take the initiative, they respond with appreciation.