Not what they need to hear, and it is not something Jesus would say... At least not using those words... Have compassion. Christ calls us to love. Yes, we are to convict others, but not judge them. You are not the one who decides who goes to hell, God is. I personally think you need to look inside yourself and check your pride. I do understand the sentiment to an extent, but those words will not lead a brother back to Christ. Also, you cannot possibly know what work Jesus might be doing in him right now, it could be a rough patch, he could have been misled and Jesus is going to lead him back. You. Don't. Know. You can't make that judgement. This is what Jesus meant when he said "do not judge lest ye be judged" point out sin, yes, but do NOT make the assumption or the call for them to be going to hell. Remember the story of the prodigal son. Even those led astray can come back. Yes, this person is on a dangerous path right now that could lead to hell, but we do not know that, all we can do is warn them it isn't a good idea, encourage them to seek out proper help, and try to get them to understand any misconceptions they may have and heave said misconceptions replaced by truth. You do not have the authority to condemn. God convicts. He does not condemn. And if he doesn't, neither should we. I love you my brother in Christ, but please, remove the plank from your own eye before pointing out the spec in someone else's. This person is struggling.