Jesus said, "I am the vine, you are the branches: He that abides in Me, and I in him, the same brings forth much fruit: for without Me you can do nothing" (Jn. 15:5).
How does a believer get into Christ in the first place? The Word is clear:
* Mark 16:16 - "He that believes and is baptized shall be saved; but he that believes not shall be damned."
* Acts 1:5 - "For John truly baptized with water; but you shall be baptized with the Holy Ghost not many days hence."
* Romans 6:3 - "Know ye not, that so many of us as were baptized into Jesus Christ were baptized into His death?"
* 1 Corinthians 12:13 - "For by one Spirit are we all baptized into one body (see v. 27), whether we be Jews or Gentiles, whether we be bond or free; and have been all made to drink into one Spirit."
* Galatians 3:27 - "For as many of you as have been baptized into Christ have put on Christ."
NOTE: This is not water baptism, but Spirit baptism; the baptism spoken of in Ephesians 4:5! This is an important distinction, in that, it is Spiritual baptism that seals a believer in Christ (Eph. 1:12-13; 4:30)! Even though a born again believer may be carnal, he remains "in Christ" (see 1 Cor. 3:1). We are not Christ-like yet, but God has begun the metamorphosis (Phil. 1:6; 1 Jn. 3:2; etc.).
So, what does it mean "to abide in Christ?" The Greek root that is most often translated "abide" in the New Testament, is μένω (menō), which is translated "abide" (61x); "remain" (16x); "dwell" (15x); "continue" (11x); "tarry" (9x); "endure" (3x); etc. Christ told His disciples that to abide in Him would result in our bearing fruit (Jn. 15:5). That meant for them (and us) to live according to the Lord's will for us, moment by moment; Jesus did His Father's will, and we are to do Christ's will. Abiding in Christ is abiding in His will! In John 15:12, Jesus said,
"This is my commandment, That ye love one another, as I have loved you."