If ye had known me (ei egnwkeite me). Past perfect indicative of ginwskw, to know by personal experience, in condition of second class as is made plain by the conclusion (an hdete) where oida, not ginwskw is used. Thomas and the rest had not really come to know Jesus, much as they loved him. From henceforth ye know him (ap arti ginwskete auton). Probably inchoative present active indicative, "ye are beginning to know the Father from now on." And have seen him (kai ewrakate). Perfect active indicative of oraw. Because they had seen Jesus who is the Son of God, the Image of God, and like God (Jo 1:18). Hence God is like Jesus Christ. It is a bold and daring claim to deity. The only intelligible conception of God is precisely what Jesus here says. God is like Christ.