If you don't know who delivered Allah SWT's divine revelation to humankind, how can you love the religion of Islam? 

According to the Prophet, no believer's faith will be complete until he loves the Prophet more than his parents, children, and himself [Bukhari & Muslim]. If we claim to be believers, yet do not study, learn, and practice the seerah and admirable traits of Prophet Muhammad, the seal of the prophets, how can we claim to be believers?

In the Qu'ran, Allah SWT describes him as:

You have a tremendous nature, verily [68:4]

It increases our love for the Prophet Muhammed by studying his seerah and character. He is the helper of truth by truth, the guide to the straight path, and shows mercy to all. In addition to establishing laws of justice, freedom, and equality, he directed people towards tawhid to worship Allah SWT correctly. As a Prophet, leader, husband, father, friend, and so much more, he sent envoys to kings and empires, delivering the message of Islam. We can gain many benefits from studying the Prophet's life, including:

Imagine being given a name and being told that you should love and follow the actions of this person. You are unlikely to do so, and if you did, you would do so robotically without emotion. Our Lord, SWT, chose the Prophet among others to bring the message of Islam, just as we spend time understanding Allah's attributes.

Quite simply, we can truly love a man by knowing about his character. It would be like someone giving you a name and telling you that you should love and follow this person's actions. Unlikely, and if you did, you would do so robotically without emotion. We must spend the same amount of time understanding Allah SWT's attributes as we do learning about the Prophet, who our Lord chose, among many others, to deliver the message of Islam.

1- Our goal is to become better versions of ourselves

The Prophet Muhammad is the most perfect human being to have ever lived. Based on his recorded life, we can see how he behaved in different roles and what admirable qualities he had.

2-To follow the sunnah

'Sunnah' refers to the practices and traditions of Prophet Muhammad. By adhering to the sunnah, we will be better believers and servants of Allah SWT. Aishah (RA) said when asked about the Prophet's character.

"The Quran was the character of the Prophet of Allah"- [Sahih Muslim]

3-Our blessings and salutations will be sent to him in his honor

Prayer on the Prophet is an excellent way to purify the heart. If Allah SWT praises a Messenger once, he praises that person ten times. Ulema (scholars) believe Allah SWT sends down His mercy on someone ten times when he praises them ten times. Hence, if you say 'Allahu alayhi was Sallam' once, ten mercies of Allah SWT come down and cleanse your heart. Please take a moment to say 'sallahu alayhi wa sallam' ten times.