Did God really say Christians have multiple personality disorder.
Yes … yes he did.
Sort of.
What He said was this: “You will receive power when the Holy Spirit has come upon you.” Acts 1:8
“Receive the Holy Spirit.” John 20:22
“Repent, and each of you be baptized in the name of Jesus Christ for the forgiveness of your sins; and you will receive the gift of the Holy Spirit.” Acts 2:38
[Jesus] “prayed for them that they might receive the Holy Spirit.” Acts 8:15
“Did you receive the Holy Spirit when you believed?” Acts 19:2
As the Apostle Paul explains, once an individual receives the Holy Spirit there are now two spirits living within the individual. The Spirit of Christ [God] and the spirit of the flesh [man]. And those two spirits struggle for dominance.
“So I say, walk by the Spirit, and you will not gratify the desires of the flesh. For the flesh desires what is contrary to the Spirit, and the Spirit what is contrary to the flesh. They are in conflict with each other, so that you are not to do whatever you want.” Galatians 5:16-17
Paul goes on to say, “I have the desire to do what is good, but I cannot carry it out. For I do not do the good I want to do, but the evil I do not want to do—this I keep on doing.” Romans 7:15.
Paul comes back to this struggle and commands us to subdue the spirit of flesh within us. “Just as you presented your members as slaves to impurity and to lawlessness, resulting in further lawlessness, so now present your members as slaves to righteousness, resulting in sanctification.” Romans 6:19
How can you know which spirit is speaking to you? Check your thoughts and desires against this list. “The works of the flesh are evident: sexual immorality, impurity, sensuality, idolatry, sorcery, enmity, strife, jealousy, fits of anger, rivalries, dissensions, divisions, envy, drunkenness, orgies, and things like these. I warn you, as I warned you before, that those who do such things will not inherit the kingdom of God.” Galatians 5:17-21
When you accept Christ as your savior you are saved, but you are not fully transformed into the image of Christ. The transformation from sinful man to Christ-like-man is a life-long process. None of us will ever fully accomplish that transformation on this side of the grave. But as you grow in Christ, others should see fruits of the spirit. Love (for God first, others next), joy, peace, patience, kindness, goodness, faithfulness, gentleness and self-control.
So yes, Christians live with split personalties. The spirit of flesh resides in impulses, acts in a reactionary manner, and seeks to have its way. The spirit of flesh is easily offended, demands its rights, and rejects Godly council. If you find yourself under the influence of the flesh, stop, drop to your knees, and pray for the Spirit of Christ to rule over your thoughts and actions. Wait until He speaks. Then, acting in ways that honor Christ, address your circumstances.
If you do this, in time, you will be transformed into the image of Christ and His Spirit will be the dominate influence others see in you.