Why don't you share with us where the limit of God's mercy lies?
"Because all those men which have seen my glory, and my miracles, which I did in Egypt and in the wilderness, and have tempted me now these ten times, and have not hearkened to my voice;
Surely they shall not see the land which I sware unto their fathers, neither shall any of them that provoked me see it:" Numbers 14:22-23
Ten times, yet consider Moses who tempted God once:
"And the LORD spake unto Moses and Aaron, Because ye believed me not, to sanctify me in the eyes of the children of Israel, therefore ye shall not bring this congregation into the land which I have given them." Numbers 20:12
"But then in the NT Peter asks:Then came Peter to him, and said, Lord, how oft shall my brother sin against me, and I forgive him? till seven times?
Jesus saith unto him, I say not unto thee, Until seven times: but, Until seventy times seven." Matt 18:21-22
To the man, Jesus said 7 times 70 meaning no really definite number that is certainly God's answer to your question. There is definite number generally, but specifically as we saw with the Israelites and Moses there is definite limit. How does God decide what a man's limit is?
"But he that knew not, and did commit things worthy of stripes, shall be beaten with few stripes. For unto whomsoever much is given, of him shall be much required: and to whom men have committed much, of him they will ask the more." Luke 12:48
This is the reason why no man is qualified to render a final judgment on the totality of a man's life as seen by God. God knows exactly what He has given each man and He knows exactly what each man has done with what he has received.