Reviving this old topic I'd like to present the flip-side as the one disowned.
I have been disowned my much of my family so I can speak on this issue from that perspective. Being a foolish and impulsive youth I repeatedly demonstrated poor judgment and caused hurt to my family with my actions. I've since lived on the lam and even gone to prison, the whole nine yards. Now, after The Lord finally got thru to me, and even led me to minister Bible study while in prison, I've come to see how far from Him my actions are and how very real He is. While I still struggle day-to-day as any honest person would admit to. (see Romans 7) I've come to a point in my life where I would have expected my upstanding Christian family to welcome me with open arms, or at the least give me the time of day as a brother in Christ. They (for the most part) have not, and have instead shown callous hatred and disregard for me. They go on attending and even helping to plant local churches, while not demonstrating to there own flesh and blood the least bit of compassion or forgiveness (both general requisites for salvation). At first it mostly struck me as really sad and as a continuing consequence of my poor past behavior. However I've recently began to realize that there is a very real possibility that they are in fact not saved, but have rather fallen victim to the self-reassuring, high and mighty, upstanding christian, social-club-church charade that is (sadly) so prevalent these days. I pray that I'm wrong, and that for whatever reason God simply does not will that I be accepted by my family, but at the same time it's very troubling that I can't see or sense any Godly love from them when it comes to me.
In answer to the question first posed in this thread; for anyone who would think it acceptable in the sight of God to disown anyone, I would hope that it would become clear that your heart shouldn't even hold such thoughts, as Christ has told us to feed and love our enemies. They may be sinners (as we all are), they may even be damned, but we are called to love them nonetheless.
The Word is not a suggestion that only applies when we feel someone has met our standards for love and compassion, and agrees with our points of view, it is a command, enforced by the Holy Spirit, whom will give you the power to love if He is truly in you.
If you feel hatred towards any person for ANY reason you need to stop and evaluate why you're yielding to the flesh and Satan instead of following Christ's example. You should feel upset by sin, but not feel hatred for the sinner. This is the example of Our Savoir: even though He knew Judas would betray Him, still he was welcomed along with the true disciples at the last supper.
"Beloved, let us love one another: for love is of God; and every one that loveth is born of God, and knoweth God.: 1 John 4:7
If you don't feel this love in your heart for those whom you disagree with or even for them who hate you, please pray that God would indwell you with His Spirit.
I am hated by some, I am called a liar and a fake by many, and still I wish they all might join me in Heaven. We don't need to agree on every point, but we must have love or we are none of His.
In closing I ask all of you who read this to please make a short prayer that my family will find the love that is Christ.
Thank you.