The word 'call' in the Bible usually applies to the call of God to follow Jesus. In 1 Corinthians 7:20 (NAS), Paul says to "let each man remain in that condition in which he was called," which suggests that this 'call' applies to all Christians. To confine the 'call' to people set apart by God for particular ministries therefore undermines our responsibilities and implies two different levels of Christians, one dedicated and destined for ministry, and the other that can get away with a lower level of dedication and obedience.
The truth, however, is there will always be some who are called to serve in one place, while others in another, some in one occupation, while others as missionaries (Lane 1984:3-4; Romans 1:7; 8:30; Acts 6:4). We cannot expect God to give us a miraculous sign to confirm our call, but we can take steps to cultivate sensitivity to God's guidance.
The Overseas Missionary Fellowship (OMF) suggests ten principles to cultivate sensitivity (Lane 1984:5-20):
1. Be prayerful
2. Let God remove our prejudices
3. Appreciate the value of timing and circumstances
4. Learn to recognize the voice of the Spirit
5. Move by faith
6. Involve others in your guidance
7. Be able to explain our sense of leading responsibly
8. Listen to the relevant testimony of others
9. Follow through on guidance received
10. Act in accordance with the Word of God
Once you have gone through the ten principles, you should be quite clear where to go from there. Pray therefore that you be willing to obey God's calling to do His will according to His plan for you.
Lane, Denis (1984) 'When God Guides', OMF: When God Guides. Robersonia, PA, USA: Overseas Missionary Fellowship, pp.1-20.