Body --> Soul --> Spirit --> God
The body is the material part. The soul is the will & intellect, given at conception, and separates from the body at natural death. The spirit is the liaison between God and us. Spirit is prayer, when we talk to God, and intuition, God speaking to us.

1 Thess 5:13
May God Himself, the God of peace, sanctify you through and through.
May your whole spirit, soul, and body be kept blameless at the coming of our Lord Jesus Christ.

From Saint Bridget bulletin:
That phrase is Saint Paul's way of referring to the entire human person.
In everyday language, 'spirit' and 'soul' are often used interchangeably.There is, however, a slight technical distinction.
The soul is that part of us which is not physical, which is the principle of life given by God, the part which will live forever.
The spirit is that part of us which inclines us towards looking beyond ourselves, beyond the physical realm, into the supernatural world.

As the Catholic apologist Tom Nash explains:
Soul when distinguished from spirit means that which gives life to a body. Spirit when contrasted with soul simply means those aspects of human life and activity that transcend our bodily limitations and so open the soul toward the supernatural life of grace.

Catholic Answers
https://www.youtube.com/watch?v=HUO9G9PNv54
Tim Staples blog "Is Man BiPartite or TriPartite?"
https://www.catholic.com/magazine/online-edition/is-man-tripartite-or-bipartite

The Catechism of the Catholic Church paragraph 367:
Sometimes the soul is distinguished from the spirit: St. Paul for instance prays that God may sanctify his people “wholly”, with “spirit and soul and body” kept sound and blameless at the Lord’s coming. The Church teaches that this distinction does not introduce a duality into the soul. “Spirit” signifies that from creation man is ordered to a supernatural end and that his soul can gratuitously be raised beyond all it deserves to communion with God.

1 Cor 2:14-15
The unspiritual man does not receive the gifts of the Spirit of God, for they are folly to him, and he is not able to understand them because they are spiritually discerned. RSVCE

Romans 8:5-13
For those who live according to the flesh set their minds on the things of the flesh, but those who live according to the Spirit set their minds on the things of the Spirit. To set the mind on the flesh is death, but to set the mind on the Spirit is life and peace. For the mind that is set on the flesh is hostile to God; it does not submit to God’s law, indeed it cannot; and those who are in the flesh cannot please God. But you are not in the flesh, you are in the Spirit, if in fact the Spirit of God dwells in you. Anyone who does not have the Spirit of Christ does not belong to him… for if you live according to the flesh you will die, but if by the Spirit you put to death the deeds of the body you will live. For all who are led by the Spirit of God are sons of God.