Summary:

Let us, then, not only call Him Lord, for that will not save us (SECOND CLEMENT).

And let those who are not found living as He taught, be understood to be no Christians, even though they profess with the lip the precepts of Christ; for not those who make profession, but those who do the works, shall be saved, according to His word (JUSTIN MARTYR). 

He loves Christ Jesus who does His will and keeps His commandments (CLEMENT OF ALEXANDRIA).

And it is necessary that they who perform this will, not hear it merely, should enter into the kingdom of heaven (HIPPOLYTUS).

Now, those who believe in Him are those who walk in the straight and narrow way, which leads to life, and which is found by few (ORIGEN).

All things are not at once to be received and assumed which are boasted of in the name of Christ, but only those things which are done in the truth of Christ (CYPRIAN). 

He showed how rash was belief in signs and wonders, which were so very easy of accomplishment by even false Christs (TERTULLIAN).

He says that even some who lead wicked lives will perform miracles in the name of Jesus, and expel demons out of men (ORIGEN).

  

For both to prophesy and to cast out devils, and to do great acts upon the earth is certainly a sublime and an admirable thing; but one does not attain the kingdom of heaven although he is found in all these things, unless he walks in the observance of the right and just way (CYPRIAN). 

The ignorance of God, i.e., “I never knew you,” is His disapproval (MELITO).