From Jon Bloom at the Desiring God Blog:

That Jesus will call them and no one will hinder them from coming. – Matthew 19:13-15

That they will respond in faith to Jesus’ faithful, persistent call. – 2 Peter 3:9

That they will experience sanctification through the transforming work of the Holy Spirit and will increasingly desire to fulfill the greatest commandments. – Matthew 22:37-39

That they will not be unequally yoked in intimate relationships, especially marriage. – 2 Corinthians 6:14

That their thoughts will be pure. – Philippians 4:8

That their hearts will be stirred to give generously to the Lord’s work. – Exodus 35:29

That when the time is right, they will GO! – Matthew 28:18-20