If your "ex" sends you a mean-spirited text they tell you "Oh you'd better not let him talk to you that way! Let him have it!!" Twenty separate people will give you twenty separate responses as to how to handle your situation.
Of course it is always good to seek wise counsel but most people are not giving you a response based on wisdom but rather on what the culture would approve of, accept and have you do.
While most people are well-intentioned, few will be guiding you in the way of the Lord. His is the only advice that you should truly seek. Yes, He speaks through others but you must understand the Word in order to know if the advice they are giving you lines up with the Lord's teaching.
"I urge you, brothers, to watch out for those who create dissensions and obstacles in opposition to the teaching you learned: avoid them." Rom 16:17.
When people tell you to cut and run from your marriage they are creating dissension and obstacles to the reconciliation of your marriage which is what God desires (and we can know this through studying His Word). AVOID THEM!
So when you need to respond to your prodigal spouse or child or any other, go to the Word and seek God's response. "Lord, how would YOU have me respond to this call, text or email?" He will answer. He will guide you.