Manvantara or saddharma is a topic of the eighth canto of "Srimad-Bhagavatam". Manvantara means the description of the eternal duties of a human being. All dharmas are good if they have a strong foundation in saddharma. The topic of the eighth canto is: what does it mean to surrender to the Lord.
The essence of all the teachings of Vedic literature is to surrender to the Lord and follow Him. We are like the Gajendra elephant and the crocodile of time is trying to devour us. Time is the cause of suffering, so the only solution to all the problems in our life is to surrender to God. It is difficult for us to surrender when everything is fine, it is difficult to pray to the Lord sincerely. Only when we have problems, then prayer comes. By association with saintly people and by strictly following the rules and regulations of varnasrama you acquire necessary sukriti, which will help you to surrender when the need will be there.
The story about Siva and Mohini Murti shows that Lord Siva wanted the Lord to prove that He is superior to Lord Siva. He wanted the Lord to show the maximum extent of His power. At the end of the story Lord Siva is humiliated by the Lord, but nevertheless he is full of gratitude towards Him.
The story of Bali Maharaj very clearly depicts the proper way to surrender to the Lord. Surrender is not a cheap process, it is a glorious process. If someone is surrendered to the Lord, He gives him everything eventually, but before that he may go through different problems.
The story of Aditi’s surrender to her guru Kasyapa Muni shows that surrender to guru is more important than surrender to the Supreme Lord. If you surrender to guru you will get the Lord Himself as a result.
The real blessing of the saint is humility. You may get or not get everything you want, but you remain humble. The ability to remain humble in any position of life is the most important quality. The pure surrendering process is only possible for humble people. Our natural position is to be surrendered to the Lord, and for this we need blessings of pure devotees.