St. Peter denied Christ three times, and rumor has it that he still got into heaven.
If you falter in difficulties then your faith is weak.
I've been thinking about this situation a lot, and I've been thinking about St. Peter a lot, wondering what I would do.
I've concluded that I, with my own resources, would have no defense or courage or confidence to keep me from submitting to Islam at the point of a sword. My only strength comes from God, and he would have to give me what it would take to stand up at the appointed time and say "I believe in God the Father Almighty, Maker of Heaven and Earth, and in His only Son, Jesus Christ my Lord..."
Peter had not received the gift of the Holy Spirit at Pentecost when he denied the Lord. I have received Confirmation, but somehow it didn't seem to make me bold and courageous like it did the Apostles of the Book of Acts.
St. Peter didn't denounce Christ and then announce his allegiance to Satan. That is the difference.