Why is "adventus" a perfect passive participle? It means "coming, by being brought."
Because that is what Christ did. He came to the earth by being brought to the earth! "Jesus Christ, God the Son, was conceived by the power of the Holy Spirit, He was born of the Virgin Mary, He suffered, He was crucified, He 'was died' and He was buried." All of those verbs in the Apostolic Creed are passive verbs which use the perfect passive participle in their perfect passive construction with "est."
...conceptus est,...natus est,...passus est,...crucifixus est,...mortuus est,...sepultus est. All those verbs take the passive form.
but...venturus est! That one is the future active participle! He will come!
Resurrexit and ascendit are perfect active verbs, indicating no mediation, just past tense, He did those actions for Himself. He rose again, He ascended, by His own action. And venturus est is future active, He will come in His own power without any mediation.
But all the other verbs indicate mediation. He had those things done to Him. He arranged for all of the those events to be done to Him, but He did not do them to Himself. He arranged to have them done, He accepted the Father's arrangement of them and the Holy Spirit's action in them. That is the great marvel of the Incarnation. God the Son decided to become a worm like us, entirely subject to nature, in perfect obedience to the Father!
The Holy Spirit did it. Mary cooperated in it. She conceived Him also, with Her flesh, and she gave Him birth. Co-Conceiver!, and Singular Deliverer! The "Mediatrix of all Graces," the "Co-Redeemer," gave birth to God, the Divine Person, Jesus Christ. He received His conception and his birth from Her. She conceived Him and She gave Him birth!
And Christ, being God, when He was conceived, God was the One Who was conceived. When He was born, God was the One Who was born in this world. That is why Mary is Theotokos, the Mother of God! God the Son did not bring Himself into the world; nor did He kill Himself when He left this world. He came in humility, He came by being brought. He made for Himself a Mother to bring Him to the world, the God-Bearer, Theotokos! He is the Superlative Emperor of the Universe, as if carried on His sedia gestatoria, when He comes.
__
CREDO in Deum Patrem omnipotentem, Creatorem caeli et terrae. Et in Iesum Christum, Filium eius unicum, Dominum nostrum, qui conceptus est de Spiritu Sancto, natus ex Maria Virgine, passus sub Pontio Pilato, crucifixus, mortuus, et sepultus, descendit ad inferos, tertia die resurrexit a mortuis, ascendit ad caelos, sedet ad dexteram Dei Patris omnipotentis, inde venturus est iudicare vivos et mortuos. Credo in Spiritum Sanctum, sanctam Ecclesiam catholicam, sanctorum communionem, remissionem peccatorum, carnis resurrectionem, vitam aeternam. Amen.
CREDO in Deum Patrem omnipotentem, Creatorem caeli et terrae. Et in Iesum Christum, Filium eius unicum, Dominum nostrum, qui conceptus est de Spiritu Sancto, natus ex Maria Virgine, passus sub Pontio Pilato, crucifixus, mortuus, et sepultus, descendit ad inferos, tertia die resurrexit a mortuis, ascendit ad caelos, sedet ad dexteram Dei Patris omnipotentis, inde venturus est iudicare vivos et mortuos. Credo in Spiritum Sanctum, sanctam Ecclesiam catholicam, sanctorum communionem, remissionem peccatorum, carnis resurrectionem, vitam aeternam. Amen.
I BELIEVE in God, the Father almighty, Creator of heaven and earth, and in Jesus Christ, His only Son, our Lord, Who was conceived by the power of the Holy Spirit and born of the Virgin Mary, suffered under Pontius Pilate, was crucified, died, and was buried; He descended into hell; on the third day He rose again from the dead; He ascended into heaven and is seated at the right hand of God, the Father Almighty; from there He will come to judge the living and the dead. I believe in the Holy Spirit, the holy catholic Church, the communion of saints, the forgiveness of sins, the resurrection of the body, and the life everlasting. Amen.
Meanwhile, today, the Feast of Saint Andrew, the Holy Father Pope Leo XIV was in Istanbul, the 1700 anniversary of the 325 AD Council of Nicea.
Pope Leo XIV is the successor of Saint Peter, "Coryphaeus."