Which had believed him (tou pepisteukota autwi). Articular perfect active participle of pisteuw with dative autwi (trusted him) rather than ei auton (on him) in verse Jo 30. They believed him (cf. Jo 6:30) as to his claims to being the Messiah with their own interpretation (Jo 6:15), but they did not commit themselves to him and may represent only one element of those in verse Jo 30, but see Jo 2:23 for pisteuw ei there. If ye abide in my word (ean umei meinhte en twi logwi twi emwi). Third-class condition with ean and first aorist (constative) active subjunctive. Are ye truly my disciples (alhqw maqhtai mou este). Your future loyalty to my teaching will prove the reality of your present profession. So the conclusion of this future condition is put in the present tense. As then, so now. We accept church members on profession of trust in Christ. Continuance in the word (teaching) proves the sincerity or insincerity of the profession. It is the acid test of life.