Friends,
I'm new to this website, and this is my first post here...so, please, bear with me.
I think we've read much here already - and had some object lessons - on-topic: why do people leave the Church?
I'm currently serving as a bishop, and suspect that my experiences are roughly applicable to the Church as a whole. With that as foundation,
1) The single largest reason I've seen for people to leave (whether recently baptized or not) is a lack of a feeling of belonging. Whether we speak of a recent convert for whom HT and/or VT is not happening; a person trying to return to activity where other members simply shun the returnee, or an otherwise active member who becomes the topic of unhappy conversation by others, the result is the same: in a ward/branch full of people, they somehow feel "alone". That is not what Father intended, nor is it how we are to treat people. As Father's children, we are to learn how to get along, and to benefit one from another. That's what families do, and we're all part of the same family.
2) I am saddened by those who hold callings, but will not fulfill them. I'm awed by those who have busy lives, fulfill callings as well as taking care of their families, and seek more service opportunities. I respect those who, in an interview, say that they'll accept the call, but feel impressed to share information from their personal life that makes clear the call is not for them at that time of their life. I've tried to learn how to conduct interviews so that I get that latter bit of information BEFORE a call is extended, and then - listening to/for the Spirit - decide whether or not to move forward with the call.
3) We sometimes receive callings to help us grow, and frequently we are NOT in the best position to determine what kind/whether growth is appropriate. I am acutely conscious of the impact I can have by picking up the phone and asking to meet with a member; I work hard to gain and keep the companionship of the Spirit so that I know what Father has in mind for a member at that stage of that member's life.
4) We all have a responsibility to help one another, irrespective of the calls we hold. We are to be family - and families help one another.
My experience so far tells me that those new to the Kingdom who are loved, respected, and supported tend not to leave - no matter whether their baptism is close to, or decades away from, their conversion.
And I know that my experiences are not unique - Elder Jay Jensen has told us that our stake has the highest retention rate of any stake in North America Northeast.
We can all help keep Father's children - if they want to stay. If we love them, care for them, and support them, they tend to want to stay.