It takes decided intention, diligent effort, life long perseverance and a reliance upon the Lord to walk in the Spirit.
Many professing Christians choose to coast in their walk with the Lord, but the truth is, there is no coasting in this life. Either we are walking in the Spirit or we are walking in the flesh, there is no middle ground to coast upon.
Those who want to be "saved just enough to get to heaven but not enough to be different from others" are deceiving themselves.
Walking in the flesh is easy. Make no effort to walk in the Spirit and we automatically walk in the flesh. Sad to say but many Christians are content with spending most of their time walking in the flesh. The get spiritual minded for Sunday morning church but step right back into their flesh walk by the time football starts after church.
God calls us to a very high calling which takes diligence and perseverance which most are unwilling to put forth. We are called to be holy, for He is holy. We are called to be perfect even as He is perfect. While we can't attain perfect holiness in this life, that's the mark we are to aim for. We must walk in the Spirit before we can head for that mark.