The first Kalima, also known as Kalima Tawheed. This is a confession one’s when he accepted Islam as a Deen, this is the way to enter in Islam. In the first part (there are two parts) of it the oneness of Allah and in the second part confession about Prophethood of Prophet Muhammad (SAW).
This is a great blessing of Allah Almighty, a great grace of Allah Almighty, He bestows his blessing on whomever He wills, this is the Kalima by reciting it a Non-Muslim becomes a Muslim if a person does not confess clearly by it, he cannot become a Muslim and cannot be called a Muslim.
It is compulsory to know and understood the meaning of Kalima Tawheed, just because of this Kalima people could be called Muslim or non-Muslim, so a person should know, what is he confessing, this is the basis of all deeds.
Reciting Kalima Tawheed or Kalima Tayyiba by his tongue actually is a man’s confess, he/she confesses that there is no god but Allah, that worship belongs to Allah alone, He is the true God, He is the only Owner, He is the Possessor of every kind of profit or loss, alone He is Sustainer, He alone the giver of life, He alone the giver of death، all kind of power is in His hands.
He should not doubt it and he should be sincere in saying this Kalima, by saying this Kalima he is announcing that he will prove to by his deeds, that now his life will be lived happily according to the principles of this Kalima, and his life will be completely obedient to the teaching of this Kalima, and he will accept everything from the core of heart.
It means when a person confesses by this Kalima, he dedicates himself to the only pleasure of Allah Almighty and entrusts his all affairs to Allah Almighty.
In Second Part talking about Prophethood of Prophet Muhammad (SAW)
In the second part of this Kalima, there is a confession of the prophethood of Prophet Muhammad (SAW), by saying this a man confess that Muhammad (SAW) son of Abdullah son of Abdul Muttalib is the servant of Allah and His last Messenger and no Prophet will come after Him.
And at the same time, he is confessing that everything that Prophet has said is true, there is no space for any doubt, and the Holy Prophet says everything by the command of Allah Almighty, I have to spend my whole life by Prophet’s instructed, and I have to stop doing what He forbid and have to follow what I have been commanded by Prophet, and I have to worship Allah alone according to the way I have been instructed by Prophet.
From the above meaning, it may have become clear to you that this Kalima, is, in fact, a covenant between Allah Almighty and His servants, in which we are confessing that Allah Almighty is our Master and we are His slaves, our life is given by Him, so we have to live according to His command, in the light of the instructions given by the prophet sent by Allah!
Who want to enter in Islam simply confess this by understanding the meaning of this Kalima.
Whoever understands the meaning of this Kalima and follows its requirement, surely he is a true Muslim and will enter Paradise.