Verse 13 of Surat as-Saff refers to the end times and Hazrat Mahdi (as)

1.

It is a great blessing for Muslims to attain Paradise in the life of the Hereafter in return for winning Allah’s approval. In addition to this great blessing in the Hereafter, there are also great blessings for Muslims in the life of this world. Allah's bestowal of faith, His bringing Muslims together, living in the End Times and being among those who will see Hazrat Mahdi (as) and the Prophet Jesus (as) are some of the most important of these. It is also a great blessing for a Muslim who has dedicated his whole life to Allah to see the moral values of the religion prevail across the world. It is of the very greatest importance for Muslims living in hardship and suffering to attain peace and comfort and lives filled with security, and for those philosophies that oppose the moral values of the religion to be completely discredited. Every true believer in Allah will feel great joy and happiness at witnessing these holy phenomena.

2.

In this part of the verse Allah tells believers of His help and of a victory in the very near future. This is a reference to the moral values of the religion (deen) ruling the world in the End Times. As we know, Hazrat Mahdi (as) will communicate the religion in a wide-ranging manner in such a way as to totally eliminate those irreligious movements (such as atheism, Darwinism, materialism, communism and Marxism…) that are opposed to the true religion. The result of this powerful communicating the religion will be an end to all attacks on Islam, to the whole world becoming spiritually enlightened thanks to this spiritual victory gained by Hazrat Mahdi (as), and, again through Allah making Hazrat Mahdi (as) his instrument, the world enjoying His support and final victory after suffering all these difficulties, hardships and fears.