The Main Evidence of Adoption is Sanctification

The main evidence of adoption is sanctification. Search, O Christian, whether the work of sanctification has passed upon your soul! Is your understanding sanctified to discern the things which are excellent? Is your will sanctified to embrace heavenly objects? Do you love where God loves and hate where God hates? Are you a consecrated person? This argues the heart of a child. God will never reject those who have his image and superscription upon them. ~ The Beatitudes

The Natural Man has No Discernment

An ignorant man looks at a star and it appears to him like a little silver spot, but the astronomer, who has his instrument to judge the dimension of a star, knows it to be many degrees bigger than the earth. So a natural man hears of the heavenly country that it is very glorious, but it is at a great distance. And because he has not a spirit of discernment, the world looks bigger in his eye. But such as are spiritual artists, who have the instrument of faith to judge heaven, will say it is by far the better country and they will hasten there with the sails of desire. “The Godly Man’s Picture” pg. 112