1 John chapter 2, verse 6 says that if we claim to abide in Him, if His life really is in us, then we will “walk in the same way that He Himself walked.”
It isn’t saying that if we are Christians, then we should try to behave like Him. It says that if we are really abiding in Him, then we WILL live like He did. Why? Because the true Christian life is not an effort to follow Jesus. The true Christian life is the overflow of the very life of Jesus living in us and through us.
The proof that we are His disciples is simple: the life of Jesus is clearly on display in our lives. And what does His life look like?