The book of John shows the problems with Christ's mental health much more plainly, it portrays him as a megalomaniac with paranoid and psychotic tendencies. If you just sit down and read the book of John you will get what I mean.
Personally I was particularly struck by John 6. Christ has amassed a following, and seems to have trouble feeding and appeasing the crowd that follows him around. It seems like the subtext is that he wants to lose the crowd, so he runs away to the mountains (6:15) where they can't follow to lose the crowd temporarily, and when he comes back, he makes a speech to his followers in which he claims to be God and demands belief in his divinity as the only way to be resurrected after they die.
The crowd is a bit miffed about Christ's suddenly weird behavior, since they knew him growing up it was hard to take him seriously as a supposed god now:
They said, “Is this not Jesus, the son of Joseph, whose father and mother we know? How can he now say, ‘I came down from heaven’?”
Christ re-iterates he's the only way to God, and then things get even more weird:
I am the bread of life. Your ancestors ate the manna in the wilderness, yet they died. But here is the bread that comes down from heaven, which anyone may eat and not die. I am the living bread that came down from heaven. Whoever eats this bread will live forever. This bread is my flesh, which I will give for the life of the world.
The people are stumped (6:52):
"How can this man give us his flesh to eat?"
Christ doubles down on this alienating cannibalism talk:
“Very truly I tell you, unless you eat the flesh of the Son of Man and drink his blood, you have no life in you. Whoever eats my flesh and drinks my blood has eternal life, and I will raise them up at the last day. For my flesh is real food and my blood is real drink. Whoever eats my flesh and drinks my blood remains in me, and I in them. Just as the living Father sent me and I live because of the Father, so the one who feeds on me will live because of me. This is the bread that came down from heaven. Your ancestors ate manna and died, but whoever feeds on this bread will live forever.”
People didn't love the boasting and claims that he was God, but they especially didn't appreciate this cannibalism angle, so his followers abandoned him:
From this time many of his disciples turned back and no longer followed him.
And there were only twelve people left who supported the clearly unwell guy who claims to be God and who requires you eat his flesh to allow him to resurrect you after you die.
The ones remaining re-affirm their loyalty, and in response Christ says:
"Have I not chosen you, the Twelve? Yet one of you is a devil!"
This comes across to me as incredibly paranoid, and in conjunction with the cannibalism and claims about being divine, they paint a picture of Christ as unhinged and mentally unwell. Of course Christians these days take communion and have normalized the cannibalism angle so it doesn't seem so crazy, but I read the book of John without the context of communion or transubstantiation, and furthermore the followers of Christ who heard his speech about eating his flesh and drinking his blood likewise didn't have that context, otherwise they would not have found it so alienating and disturbing, such that he would have lost all his followers. (I guess the twelve that remained and were on-board with the whole cannibalism and necromancy thing).
I'm apparently not the only one who thought Christ seemed mad, there are observations of this made in other parts of the gospels as well, like Mark 3:21–22:
And when his family heard it, they went out to seize him, for people were saying, "He is beside himself". And the scribes who came down from Jerusalem said, "He is possessed by Be-el′zebul, and by the prince of demons he casts out the demons".
or John 10:19–21:
There was again a division among the Jews because of these words. Many of them said, "He has a demon, and he is mad; why listen to him?" Others said, "These are not the sayings of one who has a demon. Can a demon open the eyes of the blind?"
So yeah, while there are some interesting things Christ has said (Sermon on the Mount comes to mind as saying a few good things), there are plenty of reasons to be wary of choosing Christ as a role model. You essentially have to ignore all the problems and just take the good parts to protect Christ's image, but then I would ask why you would do this if you weren't some kind of Christian. It seems unmotivated, there are other people who lived lives of more virtue and with less baggage, there is no reason to choose Christ in particular, unless you have some kind of loyalty to Christ as a figure in particular.