A road or path always leads us to something or someone. The Straight Path mentioned in this ayat is the road that leads us to Allah.
3:51 Truly! Allah is my Lord and your Lord, so worship Him. This is the Straight Path.
There is a straight and direct road to Allah. There are no bypasses or turns. It is a direct path which means that it does not stop short of its intended goal which is heaven. So who can travel on this path to Allah?
Have you ever heard someone say, “If I do enough good works, Allah will let me go to be with Him in heaven after I die?” The one who says this is blind and insults the holiness of Allah. No matter how many good works we do, we can never remove our sin.
Allah is 100% holy and no sin can come into His presence. Remember that Adam was removed from the presence of Allah because of his one sin. People who are 99.9% cannot go to heaven. In fact there is no such thing as 99.9% holiness; holiness is always 100%. Only people who have their sins removed from them can go to be with Allah. This is sad news for us, because we have all sinned. Our only hope is that Allah will create a way for us to be totally cleansed of our sin and our sinful nature.
3:52 But when Isa came to know of their disbelief, he said: “Who will be my helpers in the cause of Allah?” The disciples said: “We will be Allah’s helpers. We believe in Allah, and bear witness that we are muslims (i.e. we submit to Allah).”
3:53 Our Lord! We believe in that which You have sent down, and we follow him that You have sent (Isa). Enroll us among those who witness (to the truth)
In order to get all of the people of the world to worship Allah alone, Isa asked for some helpers. A small group of men came forward saying that they are Muslims and that they will help Isa. They said that they believe in Allah’s message and the messenger (‘Isa) that He sent down. Followers of Isa are Muslims!