15 The articular infinitive τοῦ γνῶναι (tou gnōnai, “to know”) here expresses purpose. The words “My aim is” have been supplied in the translation to emphasize this nuance and to begin a new sentence (shorter sentences are more appropriate for English style).
16 Grk “to know him, the power of his resurrection, and the fellowship of his sufferings.”

In other versions

that I may know him and the power of his resurrection, and may share his sufferings, becoming like him in his death,

I want to know Christ—yes, to know the power of his resurrection and participation in his sufferings, becoming like him in his death,

My goal is to know him and the power of his resurrection and the fellowship of his sufferings, being conformed to his death,

I want to know Christ and experience the mighty power that raised him from the dead. I want to suffer with him, sharing in his death,

so that I may know him and the power of his resurrection and the fellowship of his sufferings, being conformed to his death,

That I may know him, and the power of his resurrection, and the fellowship of his sufferings, being made conformable unto his death;

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