When Lord Krishna woke up He saw Arjuna first & then saw Duryodhana. He asked both, why they have come to Him at this moment. Both told Lord Krishna that as the battle is near they wanted Lord Krishna's help in this war. At this Lord Krishna agreed to give help to both & asked Arjuna first, how He can help him. At this Duryodhana said to Lord Krishna , "I have come before Arjuna to You so you should fulfil my desire first." At this Lord Krishna said to Duryodhana, "Though you have come before Arjuna, but I saw him first, so he should be given the first choice to ask." At this Duryodhana was perturbed that Arjuna shall ask all His armies from Him & he shall be left with nothing.
Lord Krishna told Arjuna that he has a choice, either he can take His whole army or he can choose Him alone. But when Arjuna asked Lord Krishna that he only wanted Him & nothing else, Duryodhana was perplexed & thought Arjuna to be a foolish person that he has asked for Lord Krishna alone than His big army. At this Lord Krishna told Arjuna that though he can choose Him alone but in the war He will not fight & He shall only be his charioteer. He told Arjuna that if he chooses Him alone then he shall be deprived of His whole big army. But Arjuna wanted Lord Krishna alone & not His army & accepted Lord Krishna as his charioteer.
At all this discussion, Duryodhana kept mum & thought, what Lord Krishna shall do without the army. Duryodhana actually wanted Lord Krishna's big army only & asked for that army when he got the chance. So Duryodhana got Lord Krishna's army.
Arjuna was a true devotee of Lord Krishna & knew that He was the God of the universe. He knew about all the powers of Lord Krishna & also knew that God in the form of Krishna shall save him & lead him to victory. He was having much faith in Lord Krishna than His army. Due to his faith in Lord Krishna only, ultimately he won the war while Duryodhana lost the war.
In Bhagwat Gita Lord Krishna tells Arjuna to always have faith in Him only as, whosoever, keeps faith in Lord Krishna, He always protects that devotee.
"man-mana bhava mad-bhakto
mad-yaji mam namaskuru
mam evaishyasi satyam te
pratijane priyo ’si me" (Bhagwat Gita: Chapter Eighteen verse 65)
"Lord Sri Krishna said: O Arjuna, Always think of Me, become My devotee, worship Me and offer your homage unto Me. Thus you will come to Me without fail. I promise you this because you are My very dear friend."
mam ekam saranam vraja
aham tvam sarva-papebhyo
mokshayisyami ma suchah" (Bhagwat Gita: Chapter Eighteen verse 66)
"Lord Sri Krishna said: O Arjuna, Abandon all varieties of religion and just surrender unto Me. I shall deliver you from all sinful reactions. Do not fear."
In the last verse of Bhagwat Gita, "Sanjaya" is also of the same opinion.
"yatra yogeshvarah krsno
yatra partho dhanur-dharah
tatra srir vijayo bhutir
dhruva nitir matir mama" (Bhagwat Gita: Chapter Eighteen verse 78)
"Sanjaya said: Wherever there is Krishna, the master of all mystics, and wherever there is Arjuna, the supreme archer, there will also certainly be opulence, victory, extraordinary power, and morality. That is my opinion."
So let's have complete faith in "Lord Krishna" & let's be His devotee. By having devotion in Him we shall be saved always by Him in all circumstances. Jai Sri Krishna.