Rather than speaking of the unconditional love of Abba Father, why do some in the Church focus on creating fear by preaching about sin and it’s after effect?

Well, that was an all-inclusive statement!!! Perhaps some preachers do. But yes, you have a very valid point. Sin never makes sense to a person unless he hears about the unconditional and personal love of God, the Father. Every soul should hear and experience within his heart the gentle voice of God whispering “You are precious and honoured and I love you” (cf Is 43:4). 

Sin is a kind of leprosy that prevents you from experiencing this awesome love and to make it a way of life. If the eternal fact that you are always loved is the Good News, the wage (consequence) of sin is death is the bad news. We need to hear both. We need to hear about sin so that we become aware of how much it destroys our inner joy and true happiness that our hearts long for. We need to hear about Love because we know that we have a place to turn to; no matter how messed up we have been. It is the awareness that the arms of the Father are wide open for us that gives us the courage to run back (sometimes crawl back) to experience what the Prodigal Son experienced (see Lk 15:22-24). This turning back makes our hearts capable of receiving the love that transforms us. So let us pray and hope that our priests and evangelists will preach about sin; but even more about the Love that loved us so personally.