For if he that cometh preacheth another Jesus, whom we have not preached, or if ye receive another spirit, which ye have not received, or another gospel, which ye have not accepted, ye might well bear with him.
2 Cor 11:4 (KJV)
Not all good things come from the Lord. Many times Satan tries to deceive us. And he uses his servants to disguise themselves as angels of light. Not only as people, they can also trick us by letting us think that some situation is good, which in reality is not.
We should be vigilant about this, keeping in mind that there should be no loopholes in the situation. Otherwise, it would definitely be from Satan. We should always ask wisdom from god for us to determine the REAL good.