But the Lord said to him, “Go, for he is a chosen instrument of Mine, to bear My name before the Gentiles and kings and the sons of Israel(Acts 9:15)
The only sure key to success in ministry is the voice and the guidance of the Lord.

Pray that missionaries will completely depend on the voice of the Lord for every move.
Pray for every Omega 2 supported missionaries, that they will not engage in fruitless labour.
Pray that they will discern the voice of the Lord as distinct from every other voices that minister confusion