Ignoring heresy is not an option

Wherefore it shall not weary us, to endeavor with all our might to stretch out the hand unto them. Over and above what has been already stated, I have deferred to the following book, to adduce the words of the Lord; if, by convincing some among them, through means of the very instruction of Christ, I may succeed in persuading them to abandon such error, and to cease from blaspheming their Creator, who is both God alone, and the Father of our Lord Jesus Christ. Amen.

Irenaeus of Lyons
Against Heresies, Book III
Chapter XXV

The Holy Spirit through the Church is the ladder of ascent to God

But [it has, on the other hand, been shown], that the preaching of the Church is everywhere consistent, and continues in an even course, and receives testimony from the prophets, the apostles, and all the disciples—as I have proved— through [those in] the beginning, the middle, and the end, and through the entire dispensation of God, and that well-grounded system which tends to man’s salvation, namely, our faith; which, having been received from the Church, we do preserve, and which always, by the Spirit of God, renewing its youth, as if it were some precious deposit in an excellent vessel, causes the vessel itself containing it to renew its youth also. For this gift of God has been entrusted to the Church, as breath was to the first created man, for this purpose, that all the members receiving it may be vivified; and the [means of] communion with Christ has been distributed throughout it, that is, the Holy Spirit, the earnest of incorruption, the means of confirming our faith, and the ladder of ascent to God.

…For where the Church is, there is the Spirit of God; and where the Spirit of God is, there is the Church, and every kind of grace; but the Spirit is truth.

Irenaeus of Lyons
Against Heresies, Book III
Chapter XXIV

The virgin birth was unexpected

For what great thing or what sign should have been in this, that a young woman conceiving by a man should bring forth,—a thing which happens to all women that produce offspring? But since an unlooked-for salvation was to be provided for men through the help of God, so also was the unlooked-for birth from a virgin accomplished; God giving this sign, but man not working it out. On this account

Irenaeus of Lyons
Against Heresies, Book III
Chapter XXI

He is God and man, as prophesied in Isaiah

Carefully, then, has the Holy Ghost pointed out, by what has been said, His birth from a virgin, and His essence, that He is God (for the name Emmanuel indicates this). And He shows that He is a man, when He says, “Butter and honey shall He eat;” and in that He terms Him a child also, [in saying,] “before He knows good and evil;” for these are all the tokens of a human infant. But that He “will not consent to evil, that He may choose that which is good,”—this is proper to God; that by the fact, that He shall eat butter and honey, we should not understand that He is a mere man only, nor, on the other hand, from the name Emmanuel, should suspect Him to be God without flesh.

Irenaeus of Lyons
Against Heresies, Book III
Chapter XXI

The Son of God, who is God, came from Judah

And that it is from that region which is towards the south of the inheritance of Judah that the Son of God shall come, who is God, and who was from Bethlehem, where the Lord was born [and] will send out His praise through all the earth…

…Thus he indicates in clear terms that He is God, and that His advent was [to take place] in Bethlehem, and from Mount Effrem which is towards the south of the inheritance, and that [He is] man.

Irenaeus of Lyons
Against Heresies, Book III
Chapter XX

Christ is beyond all men who ever lived, God and Lord

He who “was not born either by the will of the flesh, or by the will of man,” is the Son of man, this is Christ, the Son of the living God. For I have shown from the Scriptures, that no one of the sons of Adam is as to everything, and absolutely, called God, or named Lord. But that He is Himself in His own right, beyond all men who ever lived, God, and Lord, and King Eternal, and the Incarnate Word, proclaimed by all the prophets, the apostles, and by the Spirit Himself, may be seen by all who have attained to even a small portion of the truth. Now,

Irenaeus of Lyons
Against Heresies, Book III
Chapter XIX