Antinomista - But, sir, if an unbeliever may have a resemblance of every grace that is wrought in a believer, then it must be a hard matter to find out the difference: and therefore I conceive it is best for a man not to trouble himself at all about marks and signs.
Evangelista - Give me leave to deal plainly with you, in telling you, that although we cannot say, every one that hath a form of godliness hath also the power of godliness, yet we may truly say, that he who hath not the form of godliness, hath not the power of godliness; for though all be not gold that glitters, yet all gold doth glitter. And therefore, I tell you truly, if you have no regard to make the law of Christ your rule, by endeavouring to do what is required in the Ten Commandments, and to avoid what is there forbidden, it is a very evil sign: and, therefore, I pray you consider of it.
Thomas Boston, "Who have right to baptism, and are to be baptized?" in Complete Works of Thomas Boston, Vol. 6, p. 218:
But whenever men may speak of people's going to heaven, the sound of their feet not being heard, it seems to be no very difficult question, Whether or not a person come to eyars, can be a real saint, and yet want a form of godliness? "Although," says a grave author, "we cannot say, every one that hath a form of godliness, hath also the power of godliness, hath not the power of godliness; though all be not gold that glisterth, yet all gold doth glister." Our Lord tells us, "By their fruits ye shall know them." I shall ad, that if a person be a real believer, and yet not appear so to be, he that judgeth him a visible believer, judgeth amiss, for he is not so.