Baptism is no guarantee. While many were baptized in the early years at highland, not all stayed. Like with the baptism infants, we may be chosen by God but we do not always reflect that choice as we grow older.
As Jesus suggested in the parable of the sower, first God, then Jesus, and then the church through baptism sows the seeds of faith. Some fall along the path with no fertile ground in which to take root. The parents do not understand that the act of baptism is not a magical act but a sign of God’s invitation and that they also have a responsibility of providing for the child the continuing experience of Christian nurture within a Christian community. Without the base of a Christian community in which the family actively participates, the newly baptized are easily picked off by the scavengers of society which eat them up.
Other seed falls on the rocky ground of church social events, projects and activities. Immediately they spring up with great enthusiasm but they are so busy with the activities of church life that they have little time or opportunity to develop any depth of faith. So when the heat of the normal human frailties of a church community begins to shine upon them, they are immediately disappointed and begin to wither away because they have no roots.
Other seeds fall upon thorns of church bickering, denominational conflict, pastoral scandals, etc. and those thorns grow up like huge excuses to avoid the community of faith. They soon choke the promise of faith out of them.