God’s ‘call’ to someone to be a missionary is not authoritative in the way the Scriptures are — your ‘calling’ can never be beyond question. Nevertheless, you can be profoundly sure in your own heart. God can bring you to a conviction that, all things considered (including Scripture!), this is the path of obedience. The conviction is not infallible but, when it is of God, it brings peace.
God gives us ten means to this end. Only one is infallible — the Bible. All the others are relative, and not absolutely decisive, although they are important. Various combinations of the ten are the fuel God uses to drive the engine of his calling.
1. Know your Bible above all, and saturate your mind with it. The Bible shapes our minds for mission durability (Psalm 1:1-3) and makes us burn for Christ (Luke 24:32).
2. Know your gifts and know yourself. Every Christian has gifts (1 Peter 4:10-11). Knowing them shapes your convictions about your calling. And knowing yourself (as Paul exemplifies in Romans 7:15-24) deepens your sense of fitness for various ministries. But keep in mind that this can be overridden by other facts!
3. Ponder the needs of the world. The Christian’s heart of love is drawn out by the perceived needs of others, whether near or far. Therefore God uses what we know to awaken our desire and push us over the edge of commitment (Matthew 9:36-38).
4. Read missionary biographies and missionary frontline stories. Clearly, the Bible treats heroes of the faith as divinely appointed inspirations for our work (Hebrews 13:7). ‘Therefore, since we are surrounded by so great a cloud of witnesses, let us also lay aside every weight, and sin which clings so closely, and let us run with endurance the race that is set before us’ (Hebrews 12:1).
5. Recognise your burden. Inquire of your soul, ‘Wherein are you burdened for others?’ God sends and seeks the burden for lost people. Jesus carried such a burden: ‘O Jerusalem, Jerusalem! How often would I have gathered your children together as a hen gathers her brood under her wings’ (Luke 13:33-34). This burden was essential to his calling. What is your burden?
6. Know your circumstances — parents, health, houses, lands, children, age, etc. All of them matter in our calling, but none of them is decisive. They can be overridden. ‘Truly, I say to you, there is no one who has left house or brothers or sisters or mother or father or children or lands, for my sake and for the gospel, who will not receive a hundredfold now in this time, houses and brothers and sisters and mothers and children and lands, with persecutions, and in the age to come eternal life’ (Mark 10:29-30).
7. Pray for God to throw you where you can be best used for his glory. I say ‘throw’ because in Matthew 9:38 that is the literal meaning: ‘Pray earnestly to the Lord of the harvest to throw out labourers into his harvest’. The point is, pray! Ask God to use you to the fullest for his glory. ‘If any of you lacks wisdom, let him ask God, who gives generously to all without reproach, and it will be given him’ (James 1:5).
8. Do not neglect worship — passionate, Christ-exalting, corporate worship. The most important missionary calling that ever happened took place within the context of corporate worship: ‘While they were worshipping the Lord and fasting, the Holy Spirit said, “Set apart for me Barnabas and Saul for the work to which I have called them”‘ (Acts 13:2).
9. Listen humbly to the spiritual people in your life. They not only confirm your gifts, they are instruments of God to awaken in you possibilities and joys of missionary service that you never dreamt of (2 Timothy 1:5-7).
10. Cultivate absolute surrender of all you are and have to Christ. Such is the person that God leads to the greatest fruitfulness of life. Woe to the person who tries to be a half-Christian and never says from the heart, ‘I renounce everything for you, Lord Jesus. I am willing to go anywhere and do anything at any cost, if you will go with me and be my everlasting joy’.
This is why Jesus said, ‘Whoever does not bear his own cross and come after me cannot be my disciple … Therefore, any one of you who does not renounce all that he has cannot be my disciple’ (Luke 14:27, 33).