A call to be a missionary is much like Abraham's call. It is necessary to leave home, possessions, relatives, worldly ambitions and to go to another country to which God has led.
But one can never out-give God. Though Abraham was called to give up much, he was promised much more. God always promises blessings when we obey and follow Him.
Hebrews 13:5 says, "Let your conversation be without covetousness; and be content with such things as ye have: for he hath said, I will never leave thee, nor forsake thee."
Much the same thing was said to the people of Israel: "Be strong and of a good courage, fear not, nor be afraid of them: for the LORD thy God, he it is that doth go with thee; he will not fail thee, nor forsake thee" (Deut. 31:6).
The psalmist said, "Trust in the LORD, and do good; so shalt thou dwell in the land, and verily thou shalt be fed" (Ps. 37.3).
God promised to bless Israel, and He promises to bless us when we trust and obey. God's call for us today is that we might be separated unto Him.
"No good thing will he withhold from them that walk uprightly" (Ps. 84:11).