I highlight two controversies:
In my opinion these are not essentials and should not divide Christians.
Some Christians make a strong distinction between soul and spirit claiming that humans have three parts: (1) body, (2) soul, and (3) spirit. In this view it is the spirit of man which is truly spiritually alive; which is born again. This view runs into trouble when considering the unredeemed who also have a spirit, even if it is not activated by God's Spirit.
Verses supporting this view . . .
I pray God your whole spirit and soul and body be preserved blameless unto the coming of our Lord Jesus Christ. (1 Thessalonians 5:23)
For the word of God is quick, and powerful, and sharper than any twoedged sword, piercing even to the dividing asunder of soul and spirit, and of the joints and marrow, and is a discerner of the thoughts and intents of the heart. (Hebrews 4:12)
And Mary said, My soul doth magnify the Lord, and my spirit hath rejoiced in God my Saviour. (Luke 1:46-47)
However, there are plenty of verses which contradict this view by indicating that the soul is saved . . .
But we are not of them who draw back unto perdition [destruction]; but of them that believe to the saving of the soul. (Hebrews 10:39)
Which hope we have as an anchor of the soul, both sure and stedfast, and which entereth into that within the veil. (Hebrews 6:19)
In addition, there are passages which indicate that the soul lives spiritually and that there are only two aspects to humans, (1) body, and (2) soul, also called spirit . . .
That which is born of the flesh is flesh; and that which is born of the Spirit is spirit. (John 3:6)
For ye are bought with a price: therefore glorify God in your body, and in your spirit, which are God's. (1 Corinthians 6:20)
The body is mentioned but not the soul.
The first man Adam was made a living soul; the last Adam was made a quickening spirit. (1 Corinthians 15:45)
Confirming the souls of the disciples, and exhorting them to continue in the faith, and that we must through much tribulation enter into the kingdom of God. (Acts 14:22)
Some say that the physical body (called the flesh) is the source of sin. Examples of verses that support this . . .
Watch and pray, that ye enter not into temptation: the spirit indeed is willing, but the flesh is weak. (Matthew 26:41)
For this cause was the gospel preached also to them that are dead [unredeemed], that they might be judged according to men in the flesh, but live according to God in the spirit. (1 Peter 4:6)
However, there are verses that contradict this view . . .
Let us cleanse ourselves from all filthiness of the flesh and spirit, perfecting holiness in the fear of God. (2 Corinthians 7:1)
Here we see that the spirit is also the source of sin.
Deliver such an one unto Satan for the destruction of the flesh, that the spirit may be saved in the day of the Lord Jesus. (1 Corinthians 5:5)
If the flesh is that part of a person which is influenced by Satan to sin, why would Paul want to turn that person's flesh over to Satan so they would be saved from sin? There are two possible answers: (1) Paul wants Satan to kill that man before he loses his salvation (but later Paul exhorts the Christians to accept the man back into fellowship), and (2) Paul wants that man to experience the hardship caused by loss of fellowship to motivate him to repent and stop sinning.
In my view, the human soul has appetites (the flesh)which must be under the conscious control of the person and used in moderation according to God's law.When people merely follow the dictates of their appetites they are operating in the flesh which often results in them committing various sins. Some verses that support this . . .
It is the spirit that quickeneth; the flesh profiteth nothing: the words that I speak unto you, they are spirit, and they are life. (John 6:63)
I beseech you as strangers and pilgrims, abstain from fleshly lusts, which war against the soul. (1 Peter 2:11)