Contacting straying members
Is it correct to make members feel somehow inadequate or sinful if they do not feel they have abilities to contact other members of the church who are delinquent?
It appears that you have information about a situation which I do not. For that reason, I can respond only in general terms.
When it comes to our relationship with fellow believers, we are our “brother’s keeper” (Genesis 4:9). We have obligations and responsibilities to speak to fellow Christians when they fall into sin (Matthew 18:15-20; James 5:19-20). Love for others (1 John 3:11-24) moves us to action when sin takes a foothold in their lives.
Church leaders, including pastors, will want to encourage church members to take these responsibilities seriously and exercise Christian love and concern. Those leaders will certainly want to provide proper, God-pleasing motivation for speaking to fellow members who are not faithful in their use of the means of grace.
If, for whatever reason, Christians feel they lack the abilities to speak to straying members of the congregation, the very least—but very important work—they can do is pray for those members. God bless the work of your church in regaining the straying.