The main theme of the verse 178 is that guidance and misguidance both are from Allah. He is the creator of good and evil, guidance and misguidance. The guided are those whom Allah has given guidance and losers are those whom Allah lets go astray. This theme has been mentioned repeatedly by the Qur'an in many other verses to make the mankind know that Allah has created good and evil and has provided with clear instructions to distinguish one from the other, and with a kind of free will to choose one of the two paths. Those who willfully choose the right path and do good deeds get their reward from Allah while those who willfully take to the other path and do evil deeds are punished and sent to Hell.
Here we note that the above verse has mentioned the people of guidance in singular person while the people who are wrong and misguided have been mentioned in plural. This indicates that the path of guidance is the one true faith which was followed by all the prophets right from Adam (علیہ السلام) to the last of all Prophets ﷺ . The basic message of all the prophets has been one and the same. That is to say, the fundamentals preached by all the prophets were all same in every age. Therefore, people of any age and denomination who believed in their prophets and followed the teachings preached by them are considered by Allah belonging to one and the same category - that is, the guided. On the contrary, the ways of misguidance have been thousands in number, hence mentioned in plural in this verse.
Another point to be noted in this verse is that the people following the path of misguidance have been mentioned along with their punishment of Hell, while no mention has been made of any reward of the people following the right path. The verse mentioned them saying that they are 'the guided'. This implies that guidance, in itself, is the greatest blessing of all, which encompasses all the rewards and bounties existing in this world or in the Hereafter. The reward of guidance requires no specific mention of other rewards which are embodied therein.
For example, some great king assures some individual that he is a close friend of the king and he shall be heard and trusted by him. Certainly he enjoys the highest position among the royal officials. He does not require the achievement of a formal rank or position. Similarly, when Allah has given the title of being 'the guided' to any one, he has got all the rewards of the world. The elders have therefore said that the remembrance and worship of Allah are themselves the reward of the worship, because they are the great favour of Allah.
Any one engaged in the worship of Allah is receiving the greatest reward of Allah at the same time. Other blessings which wait for him in this world and in Paradise are second to it, as they are the fruit of this guidance.
This also explains the meaning of another Qur'anic verse in which the believers are promised to receive from their Lord their reward. It said جَزَاءً مِّن رَّبِّكَ عَطَاءً "A recompense from your Lord, a gift." Here the reward of the believers has been expressed by two different words جَزَاءً a recompense and Ata which is gift. The word جَزَاءً signifies something offered in return of some service while the word: عَطَاءً ‘Ata is a gift offered without any service or performance. This leads us to the fact that things which we take to be rewards of our performance or attainments are, in fact, the gift from our Lord. For the performance which has drawn this reward was in itself a gift from Allah Almighty who let us perform that particular service.